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The Vulnerable fishing cat Prionailurus viverrinus faces a perilous future in South-east Asia. It was last sighted in Cambodia in 2003. We deployed 16 camera traps at four sites in southern Cambodia during January–May 2015 to determine if the fishing cat was still present in the country. Eight photograph/video captures of fishing cats were recorded from the mangroves in Peam Krasop Wildlife Sanctuary and one from Ream National Park, but there were no records from Botum Sakor National Park or Prey Nup. A number of other globally threatened species were also photographed in Peam Krasop Wildlife Sanctuary: the Sunda pangolin Manis javanica , the hog deer Axis porcinus and the large-spotted civet Viverra megaspila. We learnt of the killing of an alleged fishing cat at the Sanctuary in July 2015 in retaliation for raiding fishing nets. Illegal hunting and capture of fishing cats for the wildlife trade were reported by local informants at all sites. We provide photographic and video evidence of the fishing cats and highlight the importance of Cambodia's mangroves for threatened species conservation. [ABSTRACT FROM AUTHOR]

Benthic microbial communities can play an important role in the induction of larval metamorphosis in marine invertebrates. The role of biofilms in recognizing the parental habitat is unknown for the ecologically and economically important mangrove crab Ucides cordatus , a species suffering from environmental pressures such as habitat degradation and disease. In the laboratory, we experimentally tested the influence of biofilms grown in offshore and estuarine waters on the moulting rates and developmental time to metamorphosis (TTM) of the last larval stage (megalopa) of U. cordatus . Here, we specifically studied whether: (i) megalopae of this larval-exporting species respond differently to marine (MB) and estuarine biofilms (EB), (ii) biofilms previously immersed (24 h) in adult crab-conditioned seawater (ACSW; i.e. conspecific chemical cues) exhibit a greater effectiveness (i.e. by inducing higher moulting rates and shorter TTM) on larval metamorphosis than non-immersed ones and (iii) biofilms pre-immersed (24 h) in ACSW decrease their effectiveness when incubated (24 h) in pure filtered seawater (FSW) before offering them to megalopae. U. cordatus megalopae metamorphosed to the first juvenile crab stage (JI) in response to both MB and EB, however the moulting rates were significantly higher and development TTM shorter in the presence of EB compared to MB. The metamorphosis-inducing effects were significantly enhanced when both types of biofilms were pre-immersed in ACSW, suggesting that conspecific cues can be absorbed and stored by microbial matrix. The higher inductiveness of EB compared to MB persisted after previous contact with ACSW. Furthermore, EB exhibited a significantly greater biomass production (measured as dry weight) than MB, and when immersed in ACSW, both groups of biofilms significantly increased in biomass (maintaining the hierarchy EB > MB), suggesting that water-soluble chemical substances emitted by the adult crabs may have been absorbed and metabolized by the biofilms. The metamorphic inductiveness and biomass production decreased when both groups of biofilms that were previously kept (24 h) in ACSW were thereafter immersed (24 h) in FSW. All megalopae successfully moulted to JI after accelerated TTM when reared in ACSW, regardless of presence or absence of biofilms, corroborating that conspecific stimuli are the most effective metamorphosis-stimulating cues tested so far in U. cordatus . The fact that EB improved the moulting rates and shortened the development TTM indicates that megalopae can recognize and respond to microbial assemblages typical for specific environments. This should be ecologically important during larval recruitment by facilitating settlement in appropriate habitats for the post-metamorphic development of early benthic recruits. In addition, the influence of EB could encourage colonization of new estuarine areas and aid natural recovery of U. cordatus in mangrove habitats where crab populations have suffered significant reduction due to deforestation, fishing pressure or diseases. [ABSTRACT FROM AUTHOR]

In a previous study, lethal effects of mudskipper (predator) presence were detected in the mangrove brachyuranParacleistostoma depressumbut notHaberma nanum. In addition, these effects were sex specific (male: non-significant; female: significant), suggesting differences in anti-predator behaviour. To validate this, predator avoidance strategies of the two prey species were investigated for the variables ‘species’ and ‘sex’. Ex situ responses of 40 crabs (10 per sex per species) to a mudskipper model were video-recorded. Three stimuli were given in the sequence of (A) upper torso appearance, (B) full body appearance and (C) lunge towards crab. Innate behaviour to any innocuous signal was ruled out by replacing the mudskipper model with a rectangular block. Lastly, predator recognition capabilities in terms of shape and presence of eyes were tested using five models with increasing similarity to the predator model.P. depressumandH. nanumshare the same suite of observable anti-predatory behaviours: “freeze”, “sit” or “run”. However, varied strategies were observed. Instead of flight,P. depressum“sit”, and reacted most notably in the last stimulus. In contrast,H. nanumreacted early in the onset of impending threat with “run”, with diminished responses despite the increase in signal strength. Contrary to prediction, the factor ‘sex’ was not statistically significant in either species. Predator recognition capabilities were ascertained in both prey species, as behaviours were different after the predator model was replaced.H. nanumdisplayed greater sensitivity for threat perception by withholding the flight behaviour when uncertain. This keen sense for threat recognition coupled with its flight strategy may be key to explaining the exclusion ofH. nanumfrom the predator’s diet. [ABSTRACT FROM AUTHOR]

As human populations continue to expand, increases in coastal development have led to the alteration of much of the world's mangrove habitat, creating problems for the multitude of species that inhabit these unique ecosystems. Habitat alteration often leads to changes in habitat complexity and predation risk, which may serve as additional stressors for those species that rely on mangroves for protection from predators. However, few studies have been conducted to date to assess the effects of these specific stressors on glucocorticoid (GC) stress hormone levels in wild fish populations. Using the checkered puffer as a model, our study sought to examine the effects of physical habitat complexity and predator environment on baseline and acute stress-induced GC levels. This was accomplished by examining changes in glucose and cortisol concentrations of fish placed in artificial environments for short periods (several hours) where substrate type and the presence of mangrove roots and predator cues were manipulated. Our results suggest that baseline and stress-induced GC levels are not significantly influenced by changes in physical habitat complexity or the predator environment using the experimental protocol that we applied. Although more research is required, the current study suggests that checkered puffers may be capable of withstanding changes in habitat complexity and increases in predation risk without experiencing adverse GC-mediated physiological effects, possibly as a result of the puffers' unique morphological and chemical defenses that help them to avoid predation in the wild. [ABSTRACT FROM AUTHOR]

The use of pesticides in Mozambique is increasing along with the development of agriculture in the country. Mangroves along the coastlines are ecologically important areas and vital nursing grounds for many aquatic species, several of which are of high economic value in Mozambique. Barred mudskipper ( Periophthalmus argentilineatus ), Jarbua fish ( Terapon jarbua ), Indian white prawn ( Penaeus indicus ) and the clam Meretrix meretrix were collected at three mangrove sites in the Maputo Bay area. This was complemented with samplings of the freshwater fish Mozambique tilapia ( Oreochromis mossambicus ), which was collected from three sampling sites along rivers in the surroundings of Maputo and from three sites along the Olifants and Limpopo River. Acetylcholinesterase (AChE) activity, which is an established biomarker for organophosphates and carbamate pesticides, was measured in brain and liver tissue in fish, and hepatopancreas tissue in prawn and clam. Butyrylcholinesterase (BChE) activity was also analyzed. Freshwater samples for pesticide analyses were collected in order to get an initial understanding of the classes and levels of pesticides present in aquatic systems in Mozambique. In addition to field samplings two 48-h exposure experiments were also conducted where the Indian white prawn and Barred mudskipper were exposed to malathion, and Mozambique tilapia exposed to malathion and diazinon. Field results show a significant decrease in AChE activity in fish from four of the sampling sites suggesting that pesticides present in water could be one stressor potentially affecting aquatic organisms negatively. The 48 h exposure experiment results showed a clear dose-response relationship of AChE activity in mudskipper and tilapia suggesting these species as suitable as sentinel species in environmental studies. [ABSTRACT FROM AUTHOR]

Tidal patterns of the subtropical Paranaguá Estuarine Complex, in southern Brazil, are strongly affected by episodic cold fronts and by the coastal geometry and bottom topography, resulting in high temporal variability and marked gradients in flood regime. We delimit tolerance ranges of submersion and exposure for representative plant and animal species from local mangroves and salt marshes, through a quantitative analysis of flooding patterns in three estuarine sectors. Our results are consistent with flood regime being the leading factor on how species are distributed over the intertidal flats of the PEC. Subleading factors might be related to salinity, sediment composition and nutrient flow. [ABSTRACT FROM AUTHOR]

The present study was aimed to isolate novel bioactive compounds from actinomycetes species isolated from mangrove habitats. With this connection, Pseudonocardia endophytica (VUK-10) was isolated using dilution plate technique and was examined for its secondary metabolite profiling. After successive purification and spectroscopic characterization viz., FTIR, mass, NMR, DEPT, HMQC, HMBC, and COSY spectroscopy, two compounds were identified including a semi synthetic derivative N-(4-aminocyclooctyl)-3, 5-dinitrobenzamide ( 1), obtained from the precursor of novel natural product cyclooctane-1,4-diamine ( 3), along with a known compound 3-((1H-indol-6-yl) methyl) hexahydropyrrolo [1, 2-a] pyrazine-1, 4-dione ( 2). Anti cancer activities of the characterized compounds against in vitro cancerous cell line models, MDA-MB-231, OAW-42, HeLa, and MCF-7 reveal that HELA cells are most susceptible (IC-10 nM compound 1 and 2) followed by other studied cells. On the other hand, antibacterial and antifungal activities of the studied compounds against tested pathogens revealed that there is a significant antimicrobial activity with all the tested bacterial and fungal species. Moreover, compound 1 showed the lowest MIC values against Streptococcus mutans as 4 and 16 µg/ml for Candida albicans. In conclusion, the identified novel chemical compounds in the present study may have a potential application in anticancer therapy as well as to mitigate the bacterial and fungal pathogens thus to control the infectious diseases. [ABSTRACT FROM AUTHOR]

The aim of this study of tidepool fishes was analyse variation in their use of intertidal habitats (rocky shore, mangrove and salt marsh). Specimens were collected during wet and dry periods from 18 tidepools in the three habitats. A total of 7690 specimens, belonging to 19 families and 30 species, was captured. The fish assemblage in rocky shore pools was clearly distinct from that of vegetated habitats (mangrove and salt marshes). The rocky shore fauna was dominated by permanent resident species, whereas pools in mangrove and salt marsh habitats were inhabited primarily by opportunistic and transient species. Habitat segregation by ontogenetic stage ( e.g. smaller individuals in mangroves, intermediate size classes in salt marsh and sub-adults/adults on rocky shores) indicates age-related migration in response to the physical structure of these habitats and to the natural history of each fish species. These findings are important for the development of effective conservation and management plans for intertidal fishes. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that bats are effective pollinators of mangroves in Malaysia. Bats ( Eonycteris spelaea) visited flowers of two Sonneratia species frequently, and deposited large quantities of conspecific pollen grains on stigmas. The bats are likely to be important pollinators of the two mangrove species. [ABSTRACT FROM AUTHOR]

Unique among turtles as the only exclusively estuarine species, the diamondback terrapin's ( Malaclemys terrapin) life history predisposes it to impacts from humans both on land and in the near-shore environment. Terrapins are found in salt marshes and mangroves along the Atlantic and Gulf coasts from Massachusetts to Texas. Whereas previous dietary studies have elucidated terrapins' role in temperate salt marsh food webs, food resources for terrapins inhabiting subtropical mangrove habitats have not been studied. We examined dietary resource use for diamondback terrapins in subtropical mangrove creek and island habitats within Everglades National Park, Florida, to determine foraging strategies of terrapins inhabiting south Florida (SF) mangrove systems. Fecal analysis revealed 6 categories of food items, with gastropods, crabs, and bivalves being the dominant food items. Multivariate analysis revealed differences in food sources based on habitat more so than by terrapin size class. Our results revealed that like their counterparts in temperate salt marshes, SF terrapins consume similar prey categories but with different species and abundances comprising each category. [ABSTRACT FROM AUTHOR]

The lemon shark is a large coastal species that is currently classified as Near Threatened by the International Union for the Conservation of Nature., As juveniles of the species utilize shallow, near shore habitat, they are particularly susceptible to anthropogenic impacts., The abundance, size characteristics, growth, condition factor and movement patterns of juvenile lemon sharks within the Bell Sound Nature Reserve were compared with those outside the Reserve., Sharks were more abundant within the Reserve, which also accommodated a greater proportion of smaller size classes., Although there was no difference in linear growth-rate between sharks inside and outside the Reserve, those outside exhibited higher condition factor values., It is suggested that these results are due mainly to habitat preference on the part of the sharks, with the predominantly shallower near shore waters of the Reserve offering a greater level of protection from predation., Regardless of the causative factor, the area occupied by the Bell Sound Nature Reserve appears to be highly important to the local juvenile lemon shark population., Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The paper reviews the following three types of mangrove-shrimp systems: (i) integrated with canals between platforms planted with mangrove; (ii) associated having larger areas of water and a large mangrove area; and (iii) separated, with a dyke separating ponds from forest. The variations in shrimp yield of integrated and associated systems, that is, mixed systems, are attributable to water exchange, % water surface, primary production, stocking of post-larvae, leaf litter fall and decomposition, species, cover and age of mangrove, and predators. Leaf litter from all mangrove species except Nipa palm adversely affect water quality. Leaf composition and decomposition rate vary between species; submersed leaves decompose faster. Low concentrations of decomposing leaves of certain species temporarily boosted shrimp growth. Shrimp yield has been found to be highest in ponds with 30-50% mangrove cover, but remained <400 kg ha-1 year-1, if not fed timber production peaked at 55% mangrove cover (about 10 m3 ha-1 year-1). Annual benefit-cost ratio was better in integrated systems than in associated systems, but one study found the reverse in a long-term computation. An integrated mangrove-shrimp farm of 4 ha may provide farmers with a decent livelihood in Vietnam, if contracts do not restrict recommended practices to keep water quality within the limits acceptable for shrimp. Separated systems, where mangroves are fully connected to open water, have more potential to contribute to ecological, economic and social sustainability. Enhancing the economic returns by capitalizing on ecosystem services through carbon credits and organic certification, will require support for initial investment and clustering of farms. [ABSTRACT FROM AUTHOR]

Interactions between aquaculture and the environment remain a debated issue, especially in areas where the aquaculture sector is still expanding, such as in the Mekong delta in Vietnam. In response to environmental concerns, various eco-certification schemes have been introduced for seafood, aiming to improve production practices. In order to reflect upon the criteria of these certification schemes, life cycle assessment (LCA) was applied to conventional and certified extensive organic mangrove–shrimp farms in the lower Mekong. In total, 21 organic and 20 non-organic farms were included in the study for evaluation of effects on global warming (including emissions from land transformation and occupation), eutrophication and acidification. Monte Carlo simulations and random sampling were applied to aggregate contributing processes into results. The emissions of greenhouse gasses per ton of shrimp produced were substantial for both groups, and almost solely caused by the release of carbon during mangrove land transformation. Differences in the land area needed to support shrimp production explain the discrepancy. Organic farms emitted less CO 2 -equivalents (eq.) than the non-organic farms in 75% of the Monte Carlo iterations. Acidification impacts were similar for the two groups, with higher emissions from the non-organic farms in 67% of the iterations. Meanwhile, most mangrove-integrated farms showed a net uptake of eutrophying substances, indicating that both types of mangrove–shrimp production systems are nutrient limited. In order to put the results into perspective, a comparison with intensive and semi-intensive shrimp farms was made. While the extensive mangrove–shrimp farms showed higher emissions of CO 2 -eq. per ton shrimp produced (20 tons in average for organic and non-organic farms compared to 10 tons from intensive/semi-intensive production), results indicated lower impacts in terms of both acidification and eutrophication. We recommend LCA to be used as a central tool for identifying practices relevant for eco-certification audits, including considerations for land use. However, a better understanding of the consequences of land quality change and linkages to impacts at the ecosystem level e.g. effects on ecosystem services, is needed. [ABSTRACT FROM AUTHOR]

Chen, Q.; Li, J.; Zhang, L.; Lu, H.; Ren, H., and Jian, S., 2015. Changes in the macrobenthic faunal community during succession of a mangrove forest at Zhanjiang, South China. A chronosequence was used to study the community structure of the macrobenthic faunal community during succession of the mangrove forest at Zhanjiang, South China. The four successional stages studied were (from primary to late) unvegetated shoal, the Avicennia marina community, the Aegiceras corniculatum community, and the Bruguiera gymnorrhiza + Rhizophora stylosa community. Faunal density, the diversity index, species richness, and evenness index were highest in the unvegetated shoal (189 individuals/m2, 1.97, 3.48, and 0.74, respectively, in the wet season; 105 individuals/m2, 1.77, 2.20, and 0.84, respectively, in the dry season) and lowest in the B. gymnorrhiza + R. stylosa community (35 individuals/m2, 1.04, 1.10, and 0.57, respectively, in the wet season; 46 individuals/m2, 0.86, 1.16, and 0.66, respectively, in the dry season). The values for these community parameters decreased with succession. Hierarchical clustering indicated that the distribution of the macrobenthic fauna closely corresponded with the successional stages. Correlation analysis and canonical redundancy analysis (RDA) indicated that the changes in the macrobenthic fauna with mangrove succession were associated with the aboveground vegetation (mainly crown breadth and tree height) and soil physicochemical properties (mainly soil organic matter and total nitrogen content). Several species of macrobenthic fauna were only detected in certain stages of succession, suggesting that they may be biological indicators of succession. [ABSTRACT FROM AUTHOR]

Sampling for the mangrove snails, Nerita lineata, and surface sediments was carried out from nine geographical sites of Peninsular Malaysia in April 2011. The concentrations of Lithium (Li) were determined in the shells, opercula and soft tissues of N. lineata and in the surface sediments by using ICP-MS. The ranges of Li concentrations (µg/g dry weight) were found to be 0.107-0.283 for shells, 0.021-0.177 for opercula and 0.011-0.634 for total soft tissues of N. lineata. For sediments, Li ranges were found to be between 21.84-146.22 µg/g dry weight). The distribution of Li was found to be: sediment> ST> shell> opercula. The Li sediment data in the present study were comparable with the results of Li contaminated sediments which had been previously reported in the literature and higher than those of continental crust materials and igneous rocks. There was no significant correlation (P>0.05) for the Li levels between the sediments. The snails (shells, opercula and soft tissues) and this indicated that Li is an essential metal for metabolism and thus is being regulated in the body of the snail. [ABSTRACT FROM AUTHOR]

In many animals, body size plays a crucial role in mating success in the context of competition and preference for mates. Increasing evidence has shown that male mate preference can be size-dependent and, therefore, an important driver of size-assortative mating. To test this theory, mate choice experiments were performed during the three consecutive stages of mating behaviour, namely trail following, shell mounting and copulation, in the dioecious mangrove snail, Littoraria ardouiniana. These experiments identified two possible forms of size-dependent male mate preference which could contribute to the formation of size-assortative mating in these snails. Firstly, whereas small males were unselective, large males were selective and preferred to follow mucus trails laid by large females. Alternatively, the results can also be interpreted as all males were selective and adopted a mating strategy of selecting females similar to, or larger than, their own sizes. Both small and large males also copulated for longer with large than with small females, and this was more pronounced in large males. When two males encountered a female, they engaged in physical aggression, with the larger male excluding the smaller male from copulating with the female. This study, therefore, demonstrated that size-dependent male mate preference may, along with male-male competition, play an important role in driving size-assortative mating in these mangrove snails, and this may also be the case in other species that exhibit male mate choice. [ABSTRACT FROM AUTHOR]

Abstract: In mangrove marshes in Florida, the marine snail, Cerithidea scalariformis, exhibits a tidally-induced climbing behavior in which snails forage on the substrate during low tides, then climb aerial roots of mangrove trees on incoming and high tides. Under field and laboratory conditions, we tested the conventional explanation that snails vertically migrate to avoid predators, and because populations of C. scalariformis are parasitized by a guild of larval trematodes, we quantified the additive effects of parasitism on climbing behavior. We found that snail climbing distance was significantly and positively associated with water height, with snails migrating 2.7 times higher during high tide than low tide. Climbing distance depended on the species of trematode infection, and differences in migration distance between low and high tides were reduced for two of the four trematode species, suggesting that parasitism can affect climbing behavior. In field and laboratory experiments with tethered snails, individuals experienced significant levels of predation 0–8cm above the substrate surface, which declined substantially at heights above 16cm. A laboratory experiment showed that in the presence of blue crabs, Callinectes sapidus, unparasitized snails climbed 53% higher than parasitized snails, and 37% higher than they would without the presence of a predator. Surprisingly, infected snails climbed the same distance in the presence or absence of a blue crab, suggesting that parasitism may physiologically affect a snail's ability to respond to predators. Our data show that predation and parasitism are significant driving forces behind the climbing behavior of C. scalariformis whereby parasitic infection may affect their interactions with marsh predators. Reduced climbing distance may be an adaptive benefit for the parasite that keeps snails closer to the mud surface, providing favorable conditions for free-swimming cercariae to find a second intermediate host, since cercariae can only be transmitted to the next host when the snail host is inundated. Thus, the migratory behavior of C. scalariformis is a behavioral adaptation to avoid predation and that body snatchers, such as larval trematodes, can greatly modify this behavior to increase their own evolutionary fitness. [Copyright &y& Elsevier]

To assess the potential influence of coastal development on habitat quality for estuarine nekton, we characterized body condition and reproduction for common nekton from tidal tributaries classified as undeveloped, industrial, urban or man-made (i.e., mosquito-control ditches). We then evaluated these metrics of nekton performance, along with several abundance-based metrics and community structure from a companion paper (Krebs et al. ) to determine which metrics best reflected variation in land-use and in-stream habitat among tributaries. Body condition was not significantly different among undeveloped, industrial, and man-made tidal tributaries for six of nine taxa; however, three of those taxa were in significantly better condition in urban compared to undeveloped tributaries. Palaemonetes shrimp were the only taxon in significantly poorer condition in urban tributaries. For Poecilia latipinna, there was no difference in body condition (length-weight) between undeveloped and urban tributaries, but energetic condition was significantly better in urban tributaries. Reproductive output was reduced for both P. latipinna (i.e., fecundity) and grass shrimp (i.e., very low densities, few ovigerous females) in urban tributaries; however a tradeoff between fecundity and offspring size confounded meaningful interpretation of reproduction among land-use classes for P. latipinna. Reproductive allotment by P. latipinna did not differ significantly among land-use classes. Canonical correspondence analysis differentiated urban and non-urban tributaries based on greater impervious surface, less natural mangrove shoreline, higher frequency of hypoxia and lower, more variable salinities in urban tributaries. These characteristics explained 36 % of the variation in nekton performance, including high densities of poeciliid fishes, greater energetic condition of sailfin mollies, and low densities of several common nekton and economically important taxa from urban tributaries. While variation among tributaries in our study can be largely explained by impervious surface beyond the shorelines of the tributary, variation in nekton metrics among non-urban tributaries was better explained by habitat factors within the tributary and along the shorelines. Our results support the paradigm that urban development in coastal areas has the potential to alter habitat quality in small tidal tributaries as reflected by variation in nekton performance among tributaries from representative land-use classes. [ABSTRACT FROM AUTHOR]

To assess the potential influence of coastal development on estuarine-habitat quality, we characterized land use and the intensity of land development surrounding small tidal tributaries in Tampa Bay. Based on this characterization, we classified tributaries as undeveloped, industrial, urban, or man-made (i.e., mosquito-control ditches). Over one third (37 %) of the tributaries have been heavily developed based on landscape development intensity (LDI) index values >5.0, while fewer than one third (28 %) remain relatively undeveloped (LDI < 3.0). We then examined the nekton community from 11 tributaries in watersheds representing the four defined land-use classes. Whereas mean nekton density was independent of land use, species richness and nekton-community structure were significantly different between urban and non-urban (i.e., undeveloped, industrial, man-made) tributaries. In urban creeks, the community was species-poor and dominated by high densities of poeciliid fishes, Poecilia latipinna and Gambusia holbrooki, while typically dominant estuarine taxa including Menidia spp., Fundulus grandis, and Adinia xenica were in low abundance and palaemonid grass shrimp were nearly absent. Densities of economically important taxa in urban creeks were only half that observed in five of the six undeveloped or industrial creeks, but were similar to those observed in mosquito ditches suggesting that habitat quality in urban and mosquito-ditch tributaries is suboptimal compared to undeveloped tidal creeks. Furthermore, five of nine common taxa were rarely collected in urban creeks. Our results suggest that urban development in coastal areas has the potential to alter the quality of habitat for nekton in small tidal tributaries as reflected by variation in the nekton community. [ABSTRACT FROM AUTHOR]

The article presents research which examined the diversity of littoral rotifers in the mangrove wetlands in the Pearl River estuary and Qi'ao Island in China. Topics covered include the detection of 94 species of monogont rotifers in the areas including the Encentrum marinum and Colurella adriatica. Also mentioned is the analysis of the biotopes of the rotifers and how the community structure affects their biotopes.

Mangrove bird communities in north Australia comprise relatively few passerine species compared with other arboreal habitats in the region. Mangroves are dominated by a few tree species and there are potentially few resource axes available for partitioning by terrestrial birds. Competition for limited resources is predicted to cause strong niche differentiation and a highly structured, but low diversity, bird assemblage. Using multivariate and bipartite network analyses based on 1771 foraging observations (33% of 5320 behavioral observations), we examined resource partitioning by 20 terrestrial bird species in mangroves of north Australia. The mangrove bird community largely comprised generalist insectivores that partitioned insects by size with moderate-to-high interspecific overlap in diet. Gleaning for insects was the most common foraging mode. Few species specialized on nectar. Flowers of one or more mangrove species were available in every month of the year and insect abundance was correlated with flowering peaks. Niche differentiation by birds was determined by food type and foraging mode more than by broad spatial (mangrove zones) or temporal (seasonal) segregation of the use of resources. There was little evidence of bird species saturation or species sorting, suggesting loose species packing and a lesser role than expected for species interactions and interference competition in structuring the bird assemblage in mangroves. [ABSTRACT FROM AUTHOR]

The genus Ficopomatus (Serpulidae) consists of sessile, tubicolous polychaete annelid worms that may colonize a diversity of substrata, and tolerate considerable variations in salinity. Thus, members of this genus, including Ficopomatus uschakovi, in some cases are exotic and maybe invasive. The purpose of our research was to collect and identify marine organisms associated with the submerged roots of mangrove trees in the Gulf of Urabá, Colombian Caribbean, South America. Within the Gulf, there is a welldeveloped forest of the Red Mangrove, Rhizophora mangle, along the margins of El Uno Bay. We sampled the roots of R. mangle from five stations of the bay, and we identified specimens of F. uschakovi from each of those stations. Ficopomatus uschakovi was found to be more abundant in regions of the bay that exhibit the lowest salinity. Based on a morphological comparison of the present specimens with the original species description, revised descriptions, and other records from the Indo-West Pacific, Mexican Pacific, and Venezuelan and Brazilian Caribbean, we suggest that F. uschakovi has a broader geographical distribution. Furthermore, because of this broad distribution, and the observed tolerance for low salinity in our study, we also suggest that F. uschakovi is a euryhaline species. It is also likely that F. uschakovi will be found in other localities in the Gulf of Urabá, and in other regions of the Colombian Caribbean. Thus, this record extends the distribution of the species to the Colombian Caribbean, giving the species a continuous distribution across the northern coast of South America. [ABSTRACT FROM AUTHOR]

Carbon cycling and productivity within Weno Island of Micronesia enclosed by the coral reef may be likely self-maintained and insignificantly affected by the open ocean. Therefore, it is important to understand the role of the mangrove known as providing the organic matter and habitats for many organisms in this enclosed area. In order to trace the nutritional source of fauna (mostly invertebrates) in the mangrove forest of Weno island, we analyzed the fatty acid (FA) and carbon and nitrogen stable isotopes of potential nutritional sources (mangrove leaf & pneumatophore, seagrass leaf & root, surface sediment, and particulate organic matter (POM) in water) and consumers (4 gastropods and anomura). The mangrove and seagrass contained the abundance of 18:2ω6, and 18:3ω3, whereas FAs associated with phytoplankton and bacteria were accounted for a high proportion in the surface sediment and POM. FA composition of consumers was found to be similar to those of the surface sediment, mangrove, and seagrass. These were also confirmed through the mixing model of stable isotope for contribution of nutritional sources to consumers. Overall results with the feeding types of investigated mangrove fauna indicate that investigated mangrove fauna obtained their nutrition from the various sources, i.e. the mangrove for Littorina cf. scabra, the microalgae for Strombus sp., and omnivorous Pagurus sp. and Terebralia cf. palustris. However, it is obvious that the nutrition of most species living in the mangrove ecosystem is highly dependent on the mangrove, either directly or indirectly. More detail food-web structure and function of the mangrove ecosystem would be established with the analysis of additional fauna and flora. [ABSTRACT FROM AUTHOR]

We describe the presence of the bivalve Modiolarca lateralis (Say, 1822) in six tropical ascidians Ascidia curvata, A. sydneiensis, A. panamensis, A. interrupta, Herdmania pallida and Polycarpa spongiabilis collected at depths of 1-3 m on coral reefs, mangrove roots and dock supports in Almirante Bay, Bocas del Toro, Panama (9º18'N, 82°13'W) during June-July 2011. Bivalve prevalence varied between 9-30% across species, but was mainly associated with A. panamensis, P. spongiabilis and A. interrupta. Prevalence seems to be influenced by tunic thickness rather than by the ascidian size. Bivalves varied in size (0.6-11 mm shell length), with the smallest individual found in A. sydneiensis. There were only one or two bivalves per ascidians, although a maximum of 18 was found in one A. panamensis. M. lateralis seems to behave similarly to its temperate counterparts: it has a variety of hosts, occurs mainly in the anterior region of the ascidians, and has a variable abundance per host. [ABSTRACT FROM AUTHOR]

Eight brackish water snails belonging to 5 families are described. All the samples were taken from 3 diferent types of water body. hey were taken from 1 littoral of an artificial brackish lake, 1 intertidal zone of a brackish tidal river, and 3 mangrove swamps on Qi'ao Island in the Pearl River estuary, Guangdong Province, southern China. Assiminea estuarina Habe, 1946 and Iravadia (Fairbankia) cochinchinensis Bavey & Dautzenberg, 1910 are new records for China. Cerithidea sinensis Philippi, 1848 was found in a tropical zone for the first time. The finding of Sphaerassiminea brevicula (Pfeifer, 1855) provided evidence that this species can tolerate brackish or salt water. Iravadia ornata Blanford, 1867 was the most widespread species at the sampling sites. The types of water and habitat temperature mainly affected the distribution of Melanoides tuberculata (Müller, 1774). [ABSTRACT FROM AUTHOR]

Abstract: The present study analyzed gonadal development in Crassostrea gasar from an Amazonian estuary and characterized the relationship between the reproductive cycle and the variation in abiotic factors. Samples of approximately 20 oysters were collected each month between August, 2009, and December, 2010. The study period was divided into four seasonal periods (dry, dry–rainy transition, rainy, and rainy–dry transition). The salinity, pH, temperature, and dissolved oxygen concentration of the water were measured in situ during the collection of specimens. The gonads were dissected and analyzed histologically. A total of 353 specimens were collected, of which 190 were female, 161 were male, and two were hermaphrodite. Histologically, the specimens were classified in four gonadal stages: I — immature; II — maturing; III — mature, and IV — spawned (females) and spermiated (males). Of the abiotic factors analyzed, only salinity and rainfall varied significantly over the study period, with correlations being found between these factors and gonadal maturation, suggesting that they influence the reproductive cycle of the species. A predominance of mature (stage III) and maturing individuals was recorded during the rainy and rainy–dry periods (low salinity and high rainfall), whereas immature (I) and spawned/spermiated (IV) specimens were more common during the dry and dry–rainy periods (high salinity and low rainfall). Given this, the collection of seeds for farming would be recommended during the latter period, when spawned/spermiated oysters were more common. [Copyright &y& Elsevier]

Abstract: The mangrove oyster Saccostrea palmula coexists with the pleasure oyster Crassostrea corteziensis in coastal lagoons of northwest Mexico. Recent discovery of Perkinsus marinus infecting the pleasure oyster in the region prompted evaluation of S. palmula as an alternative P. marinus host. An analysis to determine the possible presence of P. marinus in natural and cultured populations of S. palmula at four coastal lagoons in Sinaloa, Mexico was carried out during October–November 2010. Tissues from apparently healthy S. palmula were evaluated using Ray’s fluid thioglycollate method (RFTM), which revealed a Perkinsus sp. to be present in all four locations at 6.7–20.0% prevalence. Histopathological analysis of these specimens showed tissue alterations and parasite forms consistent with moderate P. marinus infection, which was confirmed by ribosomal non-transcribed spacer (NTS)-based PCR assays on DNA samples from oysters positive by RFTM and histology. DNA sequencing of amplified NTS fragments (307bp) produced a sequence 98–100% similar to GenBank-deposited sequences of the NTS from P. marinus. Fluorescent in situ hybridization for Perkinsus spp. and P. marinus corroborated the PCR results, showing clear hybridization of P. marinus in host tissues. This is the first record of P. marinus infecting a species from genus Saccostrea and the first record of the parasite from coastal lagoons in Sinaloa, Mexico. [Copyright &y& Elsevier]

The use of wetlands for processing nutrient- and organic-rich wastewater has proved effective to prevent coastal pollution in developing countries, mainly due to low running costs (low energy consumption and training requirements) and relatively high system filtration efficiency (difference of is flushed in the system minus what is flushed out, multiplied by 100). In this study we present a management model that simulate the fate of area specific organic carbon loadings in constructed mangrove wetlands (CMW). The model was calibrated and validated by measured data obtained from a newly established CMW system in Tanzania. Sewage from a nearby hotel was pumped to a primary stabilization pond with a residence time of 12h. Subsequently, sewage was discharged into 9 unvegetated cells and 9 cells planted with mangrove trees (Avicennia marina). Each group of 9 cells was split into 3 subgroups of 3 cells receiving seawater mixed with 0, 20 and 60% sewage for six months. Raw sewage was assumed to contain 0.5 (150mgBODL−1)person equivalent. The model provided a good simulation of oxygen, carbon and nutrient dynamics in the systems; primary production (by benthic microalgae and phytoplankton); and biomass change of important faunal groups (crabs and gastropods). High sewage loadings and reduced residence time decreased the system filtration efficiency. Thus a discharge of 100L of 1PE (300mgBODL−1)m−2 into the system requires a water residence time of about 60h within the CMW to achieve the Tanzanian emission standards (30mgBODL−1). Higher mangrove fauna biomass and abundance of biogenic structures (i.e. pneumatophores and crab burrows) increased carbon mineralization in the CMW sediment by up to a factor of 2. [Copyright &y& Elsevier]

Habitat-specific cues play an important role in orientation for animals that move through a mosaic of habitats. Environmental cues can be imprinted upon during early life stages to guide later return to adult habitats, yet many species must orient toward suitable habitats without previous experience of the habitat. It is hypothesized that multiple sensory cues may enable animals to differentiate between habitats in a sequential order relevant to the spatial scales over which the different types of information are conveyed, but previous research, especially for marine organisms, has mainly focused on the use of single cues in isolation. In this study, we investigated novel habitat selection through the use of three different sensory modalities (hearing, vision, and olfaction). Our model species, the French grunt, Haemulonflavolineatum, is a mangrove/seagrass-associated reef fish species that makes several habitat transitions during early life. Using several in situ and ex situ experiments, we tested the response of fish toward auditory, olfactory, and visual cues from four different habitats (seagrass beds, mangroves, rubble, and coral reef). We identified. receptivity to multiple sensory cues during the same life phase, and found that different cues induced different reactions toward the same habitat. For example, early-juvenile fish only responded to sound from coral reefs and to chemical cues from mangroves/seagrass beds, while visual cues of conspecifics overruled olfactory cues from mangrove/seagrass water. Mapping these preferences to the ecology of ontogenetic movements, our results suggest sequential cue use would indeed aid successful orientation to novel key habitats in early life. [ABSTRACT FROM AUTHOR]

Mortonagrion hirosei, a Near Threatened species, is a small damselfly recorded from several isolated sites across its entire range in eastern Asia. Previous research has indicated a strong affinity for brackish wetlands, including reedbeds and marshes, where potential predation or competition by other odonates is reduced. Results from surveys conducted in Hong Kong during 2009-2011 provide information on the habitat at a number of sites occupied by M. hirosei and report on the presence of populations in mangrove and mangrove-mosaic habitats as well as brackish marsh, often in association with a diversity of other odonates. Information is also provided on two previously unreported sites in Hong Kong. These new findings indicate that the species uses a greater diversity of habitats than the odonate-poor Phragmites reedbeds in which it has been well-studied in Japan, and consequently may be more widespread than previously supposed. Given that coastal habitats are threatened throughout its range, it is hoped this broader understanding of the species' habitat requirements will encourage others to explore other coastal sites and to aid in its conservation. [ABSTRACT FROM AUTHOR]

An important aspect in determining the ecology of a species is an understanding of its abundance and distribution. The population structure and distribution of Helograpsus haswellianus (Brachyura, Grapsidae) were evaluated over 12 months at four intertidal wetland sites that differed in vegetation and inundation. Surface activity of H. haswellianus varied over time with no consistent seasonal pattern. Sex ratios were always significantly skewed towards males, and crabs of both sexes were distributed evenly across habitats at all sites. Recruitment patterns and size frequency distributions varied significantly between sites, independent of habitats. Crabs were smaller in wetter, more sheltered areas, but size ranges overlapped between habitats. The site-specific difference in population structure and distribution of H. haswellianus indicates that the functional role of this burrowing crab may vary across wetlands. [ABSTRACT FROM AUTHOR]

Mate searching often involves chemical cues and is a key process in determining fitness in most sexually reproducing animals. Effective mate-searching strategies are, therefore, essential for individuals to avoid wasting resources as a result of misrecognition of mating partners. Marine snails in the genus Littoraria are among the most successful molluscan groups that live closely associated with mangroves. Their population densities are often low, and finding a mate within the complex three-dimensional habitat of tree leaves, branches and trunks requires an effective searching strategy. We tested whether males of L. ardouiniana and L. melanostoma located females by following their mucus trails. In the laboratory, male tracker snails followed mucus trails laid by conspecific female marker snails at a higher intensity compared with other marker–tracker sex combinations in the mating season, but not in the nonmating season, and this was more pronounced in L. ardouiniana. Male trackers did not move faster when following the trails of conspecific female markers compared with other sex combinations; however, tracker snails moved faster in the mating than in the nonmating season, although this might be related to temperature. In both species, males tracked females regardless of trail complexity, and the majority of male trackers were able to detect the direction (polarity) of the trails of conspecific females. Together with previous studies on rocky shore Littorina species, these findings suggest that sex pheromones are incorporated into mucus trails to facilitate the reproductive success of these snails. Mucus trail following is, therefore, an adaptive mate-searching strategy in intertidal gastropod molluscs, and potentially in other gastropod groups in which trail-following behaviour is prevalent. [Copyright &y& Elsevier]

Abstract: Predation rates for juveniles of three fish species, the resident cardinal fish Apogon amboinensis, vagile mojarra Gerres erythrourus and benthic resident sand goby Favonigobius reichei, were compared in a creek between a mangrove-root area (fringing area with submerged portions of mangrove roots) and a bare sand area (unvegetated central area) in the Urauchi River mangrove estuary, Iriomote island, southern Japan, by daytime tethering experiments. A. amboinensis, occurring restrictedly in the mangrove-root area, hovered inactively near mangrove roots during the day. The other two species, on the other hand, inhabited both mangrove-root and bare sand areas, G. erythrourus swimming actively and speedily in the water column and F. reichei resting immobile on the substratum, its body coloration similar to the later. The predation mortality rate of A. amboinensis was significantly lower in the mangrove-root area than the bare sand area, whereas no differences in the rates for G. erythrourus and F. reichei were found between the two microhabitats. In addition, species and individual densities of piscivorous fishes, determined from a visual census, were significantly higher in the mangrove-root area, suggesting that the potential predation risk was not necessarily lower. The lower mortality rate of A. amboinensis in such a predator-rich area may be due to their anti-predator tactic associated with mangrove structural complexity, sheltering behind mangrove roots when disturbed by predators. The similar mortality rates of the other two species between the microhabitats may have resulted from anti-predator tactics independent of mangrove vegetation structure, such as rapid flight and cryptic body coloration. [Copyright &y& Elsevier]

Abstract: To determine extreme and optimum temperature and salinity for growth in the mangrove cockle Anadara tuberculosa, we measured the scope for growth in adult cockles exposed to 16 treatments composed of combinations of four salinities (20, 30, 40, and 50psu) and four water temperatures (23, 26, 29, and 32°C). Higher clearance rates were recorded in cockles maintained at 30 and 40psu and 32°C. Consistently high clearance rates (0.9 to 1.14l g–1 h–1) were recorded in cockles held at 40psu, regardless of temperature. Absorption efficiency was higher at 20psu and lowest at 40 and 50psu. Absorbed energy increased with decreasing salinity and increasing temperature. Respiration energy was higher at low to moderate salinities (20 to 40psu) and at intermediate temperatures (26 and 29°C). The lowest respiration energy and excretion energy were recorded in cockles held at 50psu, regardless of temperature. Excretion energy was inversely related to temperature and salinity, with high values in cockles held at low salinity (20 and 30psu) and low temperature (23 and 26°C). Scope for growth was directly related to temperature and inversely related to salinity. The highest scope for growth occurred in cockles held at 32°C (120.4 to 327.3J g–1 h–1) and the lowest in cockles held at 23°C (4.3 to 84.1J g–1 h–1). The mangrove cockle can tolerate a wide range of temperature and salinity and maintain positive scope for growth. This species could be grown under a wide variety of conditions, especially in tropical lagoons receiving fresh water runoff. However it can also be grown in challenging environments such as shrimp ponds effluents and take advance of the cockle tolerance to extreme conditions. [Copyright &y& Elsevier]

Habitat heterogeneity contributes to the maintenance of species diversity; however, little is known about the influence of microhabitat heterogeneity on the diversity of mangrove invertebrates. We tested the hypothesis that the structures of benthic faunal communities differ among microhabitats because each microhabitat function differs widely according to their physical properties. The descriptors of invertebrate assemblages were determined every March (dry season) and August (wet season) of 2005, 2006, and 2007 in three different mangrove microhabitats-tidal creek, deep forest, and canopy gap-of an intertidal mangrove forest around the Sikao Creek in the Trang Province of southern Thailand. The physical properties of the selected microhabitats were studied in 2005. The properties of each microhabitat varied, especially with respect to the light intensity and sediment moisture content: the tidal creeks were wet and well-exposed to sunlight, forest interiors were moist and dark, and the canopy gaps were dry and well-exposed to sunlight. Seasonal differences in the microhabitats were also noted. The numerical abundance and biomass of benthic macrofauna differed among the microhabitats; both values were the highest in canopy gaps, and these values increased in the wet season. Despite seasonal differences, species composition differed in the three microhabitats; the majority of animals were members of the epifauna; these were surface deposit feeders. Each microhabitat functioned differently because their physical properties were disparate. A diverse benthic faunal community is formed by a combination of different functional microhabitats in mangrove ecosystems, thereby indicating that microhabitat heterogeneity should be considered as an important factor influencing the structuring of a benthic community. [ABSTRACT FROM AUTHOR]

In migratory birds, environmental conditions during the stationary period of the non-breeding season are crucial to consider because they ultimately affect the fitness of individuals by influencing their subsequent migration, breeding success and survival. Although a few studies have investigated the influence of non-breeding habitat on the capacity of individuals to cope with long-term seasonal rainfall fluctuations, it remains unknown how habitat quality and variations in rainfall abundance-at a monthly scale-interact to affect non-breeding condition of migrating birds. In this study, we examined the influence of monthly changes in rainfall abundance on body condition of non-breeding female redstarts Setophaga ruticilla living either in a high quality habitat (mangrove) or in a low quality habitat (scrub). Body condition of both mangrove and scrub redstarts showed important variations over the study period, demonstrating for the first time that body condition of non-breeding female redstarts can change rapidly in response to short-term fluctuations in rainfall. Importantly, we found that female redstarts living in mangrove were usually in better condition during periods of low rainfall compared to females living in scrub. However, body condition did not differ between mangrove females and scrub females during an episode of frequent, heavy precipitation. Importantly, our study also demonstrated that the duration of a perturbation is an important determinant of body condition in redstarts since a prolonged drought resulted in similar low body condition for birds from both habitats. Age was not correlated with body condition whatever the habitat and the rainfall conditions. Our results demonstrate that high quality habitat can temporarily reduce the deleterious effect of a short-term drought on body condition, but also, that a habitat of low quality does not constrain individuals when climatic conditions are optimal. [ABSTRACT FROM AUTHOR]

Growth is one of the key processes in the dynamic of exploited resources, since it provides part of the information required for structured population models. Growth of mangrove cockle, Anadara tuberculosa was estimated through length-based methods (ELEFAN I y NSLCA) and using diverse shell length intervals (SLI). The variability of L∞, k and phi prime (Φ') estimates and the effect of each sample were quantified by jackknife techniques. Results showed the same L∞ estimates from ELEFAN I and NSLCA across each SLI used, and all L∞ were within the expected range. On the contrary, k estimates differed between methods. Jackknife estimations uncovered the tendency of ELEFAN I to overestimate k with increases in SLI, and allowed the identification of differences in uncertainty (PE and Cv) between both methods. The average values of Φ' derived from NSCLA1.5 and length-age sources were similar and corresponded to ranges reported by other authors. Estimates of L∞, k and Φ' from NSCLA1.5 were 85.97mm, 0.124/year and 2.953 with jackknife and 86.36mm de L∞, 0.110/year de k and 2.914 de Φ' without jackknife, respectively. Based on the observed evidence and according to the biology of the species, NSCLA is suggested to be used with jackknife and a SLI of 1.5mm as an ad hoc approach to estimate the growth parameters of mangrove cockle. Rev. Biol. Trop. 59 (1): 159-170. Epub 2011 March 01. [ABSTRACT FROM AUTHOR]

The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson's solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7µm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5°C to 30°C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster's height ranged from 30 to 92mm at Point I and from 27 to 102mm at Point II, with an average of 49.0mm±9.1 (n=230) and 49.9mm±9.9 (n=237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n=237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster's percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay. Rev. Biol. Trop. 59 (1): 137-149. Epub 2011 March 01. [ABSTRACT FROM AUTHOR]

This study examines the impact of an elaborated irrigation system on the natural resources and society in the deltaic part of the Indus River in Pakistan. Time series information was collected to analyze the ecological and natural resource dynamics, and their impacts on the structure and quality of the occupations of the people in the Indus delta during pre- and post-irrigation system development periods. The information was collected through literature review, reconnaissance, structured questionnaire survey, focus group discussions, and interviews. The findings revealed that the expansion of the irrigation system and the resulting reduction in the downstream flow had their differential impacts on the various segments of downstream ecology and society. Some of the resources, for example the agricultural mudflats have been adversely affected due to the accelerated seawater intrusion that severely impinged on the paddy farms. On the other natural resources like mangroves, the impacts had been both negative and positive. On one hand, the diversity of the mangroves species had deteriorated while on other hand, the mangroves have benefited from such development because of the alleviated pressure of camel grazing as a result of the occupational change on the part of the camel herders. Furthermore, changes in the hydrological regimes had forced the paddy farmers and camel herders to switch to fishing as an alternative source of employment and income. Considering that currently about 87% people are already engaged primarily in marine fishery, this scenario is threatening the sustainability of the fishery resources as well as the livelihoods of all, the traditional and converted fishermen. The findings of the study are therefore meant to advocate the different treatments which should be accorded to the various segments of the downstream ecology and society during the planning of any remedial irrigation projects in order to mitigate the adverse impacts of the previous irrigation development strategies and of any water resources development to be carried out in the future. [ABSTRACT FROM AUTHOR]

In monitor lizards, males are typically larger than conspecific females, but body shape is usually quite similar in both sexes. This not only represents a puzzle worthy of evolutionary explanation, but also makes field sex determination of monitor lizards difficult. We asked whether subtle differences in body shape follow the same pattern as in other sexually dimorphic lizard taxa and thus can be explained by the same selective forces. We tested the hypotheses that (1) females have a longer abdomen due to fecundity selection and (2) males possess bigger heads due to intrasexual selection. We also hypothesised that (3) male monitors show a wider chests and longer upper fore-limbs to win male-male wrestling matches. We monitored ontogeny in 35 mangrove-dwelling monitors (Varanus indicus). Seventeen body measurements were taken every three months up to the age of 24-34 months. Sex was determined by an ultrasonographic imaging. We employed multiple approaches to remove the effect of size and used both confirmation and exploratory statistics. The results revealed that sexual differences in body shape were small and emerged after maturity. Females have a relatively longer abdomen while males wider chest and longer upper fore-limbs. Thus, the differences in body shape between male and female varanid lizards may be attributed to both fecundity and sexual selection. [ABSTRACT FROM AUTHOR]

Abstract: Metallothioneins (MTs) are a family of low-molecular-weight cysteine-rich proteins and are thought to play possible roles in metal metabolism or detoxification. To evaluate the roles of metallothioneins in metal homeostasis or tolerance in Avicennia marina, a real-time quantitative PCR protocol was developed to directly evaluate the expression of AmMT2 mRNA, when A. marina seedlings were exposed to different concentrations of zinc (Zn), copper (Cu) or lead (Pb) for 3 and 7d. Real-time quantitative PCR results indicated that the regulation of AmMT2 mRNA expression by Zn, Cu and Pb was strongly dependent on concentration and time of exposure. A significant increase in the transcripts of AmMT2 gene was also found in response to Zn, Cu and Pb, at least under some experimental conditions. When AmMT2 was overexpressed in Escherichia coli BL21 as a carboxy-terminal extension of glutathione-S-transferase (GST), the transgenic bacteria showed an increased tolerance to Zn, Cu, Pb and Cd exposure as compared to control strains. Moreover, GST-AmMT2 was purified from E. coli cells grown in the presence of 400μM Zn, Cu, Pb or Cd. The purified GST-AmMT2 fusion protein could bind higher levels of all four metals than GST alone. Taken together, these data support the hypothesis that AmMT2 may be involved in processes of metal homeostasis or tolerance in A. marina. [Copyright &y& Elsevier]

Abstract: The genus Littoraria is one of very few molluscan groups that are closely associated with mangroves. We document its global evolutionary radiation and compare biogeographic patterns with those of mangrove plants, based on phylogenetic and fossil evidence. Using sequences from three genes (nuclear 28S rRNA, mitochondrial 12S rRNA and COI) we reconstruct a phylogeny of 37 of the 39 living morphospecies. Six monophyletic subgenera are defined (Bulimilittorina, Lamellilitorina, Littoraria, Palustorina, Protolittoraria, Littorinopsis) and we synonymize L. coccinea and L. glabrata. A deep division between Palustorina from the Indo-West Pacific and Littoraria from the Atlantic and Eastern Pacific is estimated by a Bayesian relaxed-clock method to be of Middle Eocene to Palaeocene age (43.2–62.7Ma), which far predates the Early Miocene (18Ma) closure of the Tethyan Seaway; this, as in mangrove plants, may reflect vicariance by climatic cooling, rather than tectonic processes. The age of Littoraria angulifera in the Atlantic is, however, consistent with Early Miocene vicariance of a Tethyan ancestor. We infer that speciation events are mainly of Miocene or older age, and that diversification has not been driven by depletion of mangrove habitats during recent glacial intervals. Parsimonious reconstruction of ancestral habitats suggests that the genus has inhabited mangrove or wood substrates since its origin, while the rock-dwelling habit of the four members of Protolittoraria is derived. Three species span the Eastern Pacific Barrier, and one is amphi-Atlantic, consistent with a long larval phase of up to 10weeks. Allopatric speciation is inferred, but usually with subsequent range overlap. Ovoviviparity (interpreted as an adaptation to life in mangroves) has arisen twice. [Copyright &y& Elsevier]

Abstract: Deforestation of mangrove forests is common occurrence worldwide. We examined fish assemblage composition in three mangrove creek systems in Tanzania (East Africa), including two creeks where the upper parts were partly clear-cut of mangrove forest due to the construction of solar salt farms, and one creek with undisturbed mangrove forest. Fish were caught monthly for one year using a seine net (each haul covering 170m2) within three locations in each creek, i.e. at the upper, intermediate and lower reaches. Density, biomass and species number of fish were lower in the upper deforested sites compared to the mangrove-fringed sites at the intermediate and lower parts in the two creeks affected by deforestation, whereas there were no differences among the three sites in the undisturbed mangrove creek system. In addition, multivariate analyses showed that the structure of fish assemblages varied between forested and clear-cut sites within the two disturbed creeks, but not within the undisturbed creek. Across the season, we found no significant differences except for a tendency of a minor increase in fish densities during the rainy season. At least 75% of the fishes were juveniles and of commercial interest for coastal fisheries and/or aquaculture. Mugil cephalus, Gerres oyena and Chanos chanos were the most abundant species in the forested sites. The dominant species in the clear-cut areas were M. cephalus and Elops machnata, which were both found in relatively low abundances compared to the undisturbed areas. The conversion of mangrove forests into solar salt farms not only altered fish assemblage composition, but also water and sediment conditions. In comparison with undisturbed areas, the clear-cut sites showed higher salinity, water temperature as well as organic matter and chlorophyll a in the sediments. Our results suggest that mangrove habitat loss and changes in environmental conditions caused by salt farm developments will decrease fish densities, biomass and species numbers as well as alter the overall fish assemblage composition in the salt farm area but not downstream in the creek. [Copyright &y& Elsevier]

The description of a new cryptic member of the mangrove monitor (Varanus indicus) (Daudin, 1802) group from Indonesia presents a refinement of the systematic concept for a polytypic complex of closely related species. The new species is recognised on the basis of morphological and molecular evidence. It is so far known only from the type locality, the remote Talaud Islands, located between Sulawesi, Halmahera and Mindanao at the outer boundary of the Wallacea transition zone between the Oriental and Australian faunal regions. While the descriptions of several sibling and mostly sympatric species within the last 15 years have not affected the range of V. indicus, here, we demonstrate that morphologically distinct island populations represent independent evolutionary lineages and warrant specific recognition as distinct species within an evolving superspecies complex. In addition, some basic natural history information is provided for the new species based on observations at the type locality. These systematic and zoogeographic investigations reveal shortcomings in the current knowledge concerning the diversity and endemism of Indo-Australian monitor lizards, particularly within the Wallacean region. [ABSTRACT FROM AUTHOR]

Seven strains of a novel Kluyveromyces species were isolated from seven water samples collected from a mangrove forest. Analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene sequences revealed that the sequences of five strains (RS8T, RS20, RS54, RV42 and RV89) were identical and differed from the other two strains (RS65 and RV153) by only one nucleotide substitution in 544 nucleotides (nt). The closest species in terms of pairwise sequences similarity was Kluyveromyces aestuarii, but the level of nucleotide substitution (six to seven nucleotide substitutions in 544 nt) was sufficient to justify the description of a separate species. The phylogenetic tree based on the sequence of the D1/D2 domain of the LSU rRNA gene rather suggested that the new species is a sister species of K. aestuarii and forms a clade with the other six recognized species of Kluyveromyces. Sequence analysis of the internal transcribed spacer (ITS1–5.8S rRNA gene–ITS2) region supported their distinct status as a species. The phenotypic characteristics of the seven strains were typical of the genus Kluyveromyces. On this basis, the seven strains were assigned to a single novel species of the genus Kluyveromyces, for which the name Kluyveromyces siamensis sp. nov. is proposed. The type strain is RS8T (BCC 25962T=NBRC 103859T=CBS 10860T). [ABSTRACT FROM AUTHOR]

The extent and function of coastal mangrove ecosystems are likely to be influenced by future changes in sea level. Multiple proxies of past mangrove ecosystems preserved in a 780 cm long peat core (TCC2) taken from Twin Cays, Belize, record palaeoecological changes since ∼8000 cal. yr BP. The proxies included pollen and the stable-isotope (C, N and O) compositions of mangrove leaf fragments. Rhizophora mangle (red mangrove) has been dominant at this site on Twin Cays for over ∼8000 years. Variations in δ13C and δ15N suggest past changes in stand structure between dwarf, transition and tall R. mangle through the Holocene. Marked changes in the δ18O (up to ∼4‰) of mangrove leaf fragments throughout TCC2 most likely record variations in the proportion of seawater versus precipitation taken up by past mangroves, reflecting the degree of inundation of the site with seawater resulting from changes in the rate of Holocene sea-level rise. Notably, a decline in peat accumulation rate at ∼7200 cal. yr BP correlates with a decrease in the rate of rise in sea level. This was not accompanied by a marked change in the pollen assemblages. However, changes in assemblage composition began to occur ∼6300 cal. yr BP, with an increase in Myrsine-type and Avicennia germinans (black mangrove) pollen. An increase in the δ18O between 6100 and 5300 cal. yr BP, which correlates with other records from Central America, indicates a significant increase in the rate of rise in sea level. [ABSTRACT FROM AUTHOR]

Three mangrove restoration methods were tested at Nu'uuli, Tutuila Island, American Samoa. Since clearing 27 years ago converted the mangrove into a mudflat, the ecosystem was sufficiently altered that it could not self-correct; the ecosystem showed no natural regrowth despite an ample supply of propagules. While several years of monitoring may ultimately be required to determine the project's success, and several decades could be required to fully return the full suite of functions, the project's low-cost, nontechnical restoration techniques, using readily available materials, have proven to be modestly successful, with 38% sapling survival after six months. Several years of monitoring will be necessary to determine if the restoration site's small elevation deficit relative to a reference site ultimately requires modifying the site's physical structure to correct the hydrology. Direct community participation in the project was critical to reduce the risk of human disturbance of the restoration site. One year project costs were about USD $2,150 or USD $13,030 ha-1. Labor comprised 84% of expenses; replicating the restoration project in developing countries would cost less due to lower wage levels. Six months after initial restoration activities, there was a highly significant difference between Bruguiera gymnarrhiza and Rhizophara mangle sapling survival, with 21% and 45% of the original 42 R. mangle and 95 B. gymnarrhiza saplings remaining, respectively. The lower B. mangle survival may have resulted from an unavoidable need to source saplings from an area with different environmental conditions than the restoration site. Saplings were transplanted into tires filled with sediment as a simple, low-cost method to raise the elevation of the sediment surface. Saplings were also transplanted adjacent to rebar and without any support mechanism. There was no significant difference in sapling survival by treatment for individual or combined species. The restoration project is a model for the community-based, simple, low-cost approaches to ecological restoration needed in the region. Pilot projects using similar techniques may be worth pursuing at the other 15 Pacific Island countries and territories where mangroves are indigenous. [ABSTRACT FROM AUTHOR]