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Located along the Argentine coastline of northern Patagonia, are San Matías (SMG) and San José (SJG) gulfs; although they are regarded as an area with a high-priority conservational status, knowledge on their diversity is currently fragmentary. Studies on molluscs from this area have been historically centred in economic resources and few works have referred to non-commercial species. The present study aims to document the biological diversity of molluscs at the SMG/SJG area, in order to determine the significance of these two gulfs in the context of the Argentine marine fauna; to evaluate how well represented is this fauna in three protected areas; and to compare the fauna present in the protected areas with that of a non-protected area. For that purpose, molluscs coming from 132 sampling stations, ranging from the intertidal to 170 m depth, were studied, and a thorough bibliographic compilation was performed. A total of 196 species of molluscs are reported for the area. Surprisingly, almost one third of these species lacked previous records for SMG/SJG, including several new/possibly new species. The three studied protected areas contain 88.3% of the species recognised for the entire SMG/SJG area. Although several species appear as exclusive from one of these three areas, many of them are also present in an intermediately located, non-protected area. Molluscan diversity at the SMG/SJG area is greater than previously thought, comprising about 41.4% of the bivalves and 37.8% of the gastropods present in the Argentine shelf; thus suggesting that the area may be considered as a hot-spot of diversity in the Argentine Sea. [ABSTRACT FROM AUTHOR]

The article presents a study which described the species of Scomberesox scombroides (Richardson, 1843) caught in the coastal waters of Patagonia in the Southwest Atlantic on June 10, 2007. The variables considered include geographical distribution, preservation process used, length of the sample specimen, characteristics of the fins, and comparison with existing records. The migration pattern of Scomberesox by means of the Benguela Current is discussed.

The mangrove crab Aratus pisonii was considered to have an amphi-American distribution; however, a recent study revealed that the Eastern Tropical Pacific populations were genetically distinct, thus representing a new species: Aratus pacificus. These species separated by the Isthmus of Panama have diverged under different environmental conditions that may have influenced their reproductive biology. As the available information about this genus concerns almost exclusively the Caribbean species, the aim of the present study was to analyse and compare reproductive aspects of A. pacificus and A. pisonii obtained from both the Pacific and Caribbean coasts of Costa Rica. Females were collected from April 2011 to April 2012, and reproductive features such as breeding season, size distribution of ovigerous females, fecundity, reproductive output, embryo volume and embryo water content were assessed. Both species produced embryos during the entire sampled period. Most females of A. pacificus carrying embryos close to hatching were found during the rainy season. Ovigerous females of A. pisonii were substantially larger and reached sexual maturity at a larger size than females of A. pacificus. Embryo production started in A. pacificus at a smaller female size than in A. pisonii. As fecundity increased with female size, the average fecundity was lower in A. pacificus. Females of A. pisonii produced larger embryos, which might be related to lower food availability: higher energy content in the embryo enhances the chances of larval survival. These data regarding reproductive features of the Pacific and Caribbean species support the conclusion to separate A. pacificus from A. pisonii. [ABSTRACT FROM AUTHOR]

This paper discusses the current state of underwater optical imaging in the context of physics, technology, biology, and history. The paper encompasses not only the history of human's ability to see underwater, but also the adaptations that various organisms living in oceans or lakes have developed. The continued development of underwater imaging systems at military, commercial, and consumer levels portends well for both increased visibility and accessibility by these various segments. However, the fundamental limits imposed by the environment, as currently understood, set the ultimate constraints. Physics, biology, computer modeling, processing, and the development of technology that ranges from simple cameras and lights to more advanced gated and modulated illumination are described. The future prospects for continuing advancements are also discussed. [ABSTRACT FROM PUBLISHER]

I summarize marine studies on plastic versus adaptive responses to global change. Due to the lack of time series, this review focuses largely on the potential for adaptive evolution in marine animals and plants. The approaches were mainly synchronic comparisons of phenotypically divergent populations, substituting spatial contrasts in temperature or CO2 environments for temporal changes, or in assessments of adaptive genetic diversity within populations for traits important under global change. The available literature is biased towards gastropods, crustaceans, cnidarians and macroalgae. Focal traits were mostly environmental tolerances, which correspond to phenotypic buffering, a plasticity type that maintains a functional phenotype despite external disturbance. Almost all studies address coastal species that are already today exposed to fluctuations in temperature, pH and oxygen levels. Recommendations for future research include (i) initiation and analyses of observational and experimental temporal studies encompassing diverse phenotypic traits (including diapausing cues, dispersal traits, reproductive timing, morphology) (ii) quantification of nongenetic transgenerational effects along with components of additive genetic variance (iii) adaptive changes in microbe-host associations under the holobiont model in response to global change (iv) evolution of plasticity patterns under increasingly fluctuating environments and extreme conditions and (v) joint consideration of demography and evolutionary adaptation in evolutionary rescue approaches. [ABSTRACT FROM AUTHOR]

Ocean warming can alter natural selection on marine systems, and in many cases, the long-term persistence of affected populations will depend on genetic adaptation. In this study, we assess the potential for adaptation in the sea urchin Heliocidaris erythrogramma armigera, an Australian endemic, that is experiencing unprecedented increases in ocean temperatures. We used a factorial breeding design to assess the level of heritable variation in larval hatching success at two temperatures. Fertilized eggs from each full-sibling family were tested at 22 °C (current spawning temperature) and 25 °C (upper limit of predicted warming this century). Hatching success was significantly lower at higher temperatures, confirming that ocean warming is likely to exert selection on this life-history stage. Our analyses revealed significant additive genetic variance and genotype-by-environment interactions underlying hatching success. Consistent with prior work, we detected significant nonadditive (sire-by-dam) variance in hatching success, but additionally found that these interactions were modified by temperature. Although these findings suggest the potential for genetic adaptation, any evolutionary responses are likely to be influenced (and possibly constrained) by complex genotype-by-environment and sire-by-dam interactions and will additionally depend on patterns of genetic covariation with other fitness traits. [ABSTRACT FROM AUTHOR]

Organisms are expected to adapt or move in response to climate change, but observed distribution shifts span a wide range of directions and rates. Explanations often emphasize biological distinctions among species, but general mechanisms have been elusive. We tested an alternative hypothesis: that differences in climate velocity--the rate and direction that climate shifts across the landscape--can explain observed species shifts. We compiled a database of coastal surveys around North America from 1968 to 2011, sampling 128 million individuals across 360 marine taxa. Climate velocity explained the magnitude and direction of shifts in latitude and depth much more effectively than did species characteristics. Our results demonstrate that marine species shift at different rates and directions because they closely track the complex mosaic of local climate velocities. [ABSTRACT FROM AUTHOR]

An isolated exopod in uncompressed three-dimensional "Orsten"-type preservation from the Cambrian of Australia represents a new species of Marrellomorpha, Austromarrella klausmuelleri gen. et sp. nov. The exopod is composed of at least 17 annuli. Each of the proximal annuli carries a pair of lamellae: one lamella on the lateral side and one on the median side. The distal annuli bear stout spines in the corresponding position instead of lamellae, most likely representing early ontogenetic equivalents of the lamellae. The new find extends the geographical range of the taxon Marrellomorpha. Additionally, it offers a partial view into marrellomorph ontogeny. The occurrence of a marrellomorph fragment in "Orsten"-type preservation provides new palaeo-ecological insights into the possible connections between the "Orsten" biotas and other fossil Lagerstätten. Finding such connections is necessary for understanding the complex ecosystems of early Palaeozoic times. [ABSTRACT FROM AUTHOR]

Increasing experience in long-lived species is fundamental to improving breeding success and ultimately individual fitness. Diving efficiency of marine animals is primarily determined by their physiological and mechanical characteristics. This efficiency may be apparent via examination of biomechanical performance (e.g. stroke frequency and amplitude, change in buoyancy or body angle, etc.), which itself may be modulated according to resource availability, particularly as a function of depth. We investigated how foraging and diving abilities vary with age in a long-lived seabird. During two breeding seasons, small accelerometers were deployed on young (5year old) and older (8/9year old) brooding king penguins (Aptenodytes patagonicus) at the Crozet Archipelago, Indian Ocean. We used partial dynamic body acceleration (PDBA) to quantify body movement during dive and estimate diving cost. During the initial part of the descent, older birds exerted more effort for a given speed but younger penguins worked harder in relation to performance at greater depths. Younger birds also worked harder per unit speed for virtually the whole of the ascent. We interpret these differences using a model that takes into account the upthrust and drag to which the birds are subjected during the dive. From this, we suggest that older birds inhale more at the surface but that an increase in the drag coefficient is the factor leading to the increased effort to swim at a given speed by the younger birds at greater depths. We propose that this higher drag may be the result of young birds adopting less hydrodynamic postures or less direct trajectories when swimming or even having a plumage in poorer condition. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Tracking technologies are often proposed as a method to elucidate the complex migratory life histories of migratory marine vertebrates, allowing spatially explicit threats to be identified and mitigated. We conducted a global analysis of foraging areas of adult green turtles ( Chelonia mydas) subject to satellite tracking ( n= 145) and the conservation designation of these areas according to International Union for Conservation of Nature criteria. Location The green turtle has a largely circumtropical distribution, with adults migrating up to thousands of kilometres between nesting beaches and foraging areas, typically in neritic seagrass or algal beds. Methods We undertook an assessment of satellite tracking projects that followed the movements of green turtles in tropical and subtropical habitats. This approach was facilitated by the use of the Satellite Tracking and Analysis Tool (http://www.seaturtle.org) and the integration of publicly available data on Marine Protected Areas (MPAs). Results We show that turtles aggregate in designated MPAs far more than would be expected by chance when considered globally (35% of all turtles were located within MPAs) or separately by ocean basin (Atlantic 67%, Indian 34%, Mediterranean 19%, Pacific 16%). Furthermore, we show that the size, level of protection and time of establishment of MPAs affects the likelihood of MPAs containing foraging turtles, highlighting the importance of large, well-established reserves. Main conclusions Our findings constitute compelling evidence of the world-wide effectiveness of extant MPAs in circumscribing important foraging habitats for a marine megavertebrate. [ABSTRACT FROM AUTHOR]

The article discusses various research studies related ecology and its conservation. A study of the Pacific leaping blenny in Guam provides insights on how aquatic animals adapt on land. The use of wildfire retardants in the U.S. is under scrutiny as the May 2011 environmental impact estatement (EIS) does not provide proof that they improve initial attacks. A study by the U.S. Government Accountability Office (GAO) claims that climate engineering offers no viable solution for global warming.

Most people are familiar with the concept that animals come in all shapes and sizes and that the body plan of some animals can completely transform during their lifetime. Well-known examples of such complex life cycles of terrestrial animals include butterflies and frogs. Many people are unaware, however, that complex life cycles are exceedingly prevalent in marine environments. Marine invertebrates, such as sea urchins, sea stars, and crabs, all have a microscopic pelagic larval stage that looks nothing at all like the familiar adult form. The authors have developed a lesson to teach students about complex life cycles using crab larvae and adult crabs. This lesson allows 3rd- to 6th-grade students to compare and contrast body plans while learning about adaptations the larvae and adults have made to their respective habitats. Throughout the lesson, students practice skills important for scientific inquiry: making observations, drawing what they see, asking and answering questions, and learning to use scientific tools such as microscopes. [ABSTRACT FROM AUTHOR]

Air-breathing marine animals, including sea turtles, utilise two fundamentally different environments (i.e. sea surface and underwater) during migration. Many satellite telemetry studies have shown travel paths at relatively large spatio-temporal scales, discussing the orientation and navigation mechanisms that guide turtles. However, as travel paths obtained by satellite telemetry only reflect movements at the surface, little is known about movements and orientation ability underwater. In this study, to assess orientation ability both at the surface and underwater, fine-scale 3-D movements of free-ranging loggerhead turtles Caretta caretta were reconstructed by using multi-sensor data loggers. Video systems ('Crittercam') were also used to record the behaviour of the turtles and the visual information surrounding the turtles. During August and October in 2006 and 2007, eight turtles were released from Otsuchi Bay, Japan (39°20'30N, 141°56'00E), and a total of 118h of 3-D movements were reconstructed. Turtles maintained highly straight-line courses (straightness index >0.95) during 41% of the total duration (i.e. 'travelling periods'). During travelling periods, turtles swam continuously, maintaining unidirectional heading throughout dives whereas turtles changed heading remarkably at the surface. Despite highly directional movements during dives, travel direction tended to shift by the end of dives lasting 10 minutes or more. Such deflections seemed to be compensated during subsequent surfacing periods because there was a negative relationship between changes in travel direction arising during dives and subsequent surfacing periods. Therefore, remarkable changes in heading at the surface could be interpreted as direction-searching behaviour. Our results suggested that turtles undertaking directional travel were more dependent on directional information that was reliable at the surface. [ABSTRACT FROM AUTHOR]

Sex allocation by simultaneous hermaphrodites is theoretically influenced by selfing rate, which is in turn influenced by the benefits of enhanced genomic transmission and reproductive assurance relative to the cost of inbreeding depression. The experimental investigation of these influences in seed plants has a rich pedigree, yet although such an approach is equally relevant to colonial invertebrates, which globally dominate subtidal communities on firm substrata, such studies have been scarce. We reared self-compatible genets of the marine bryozoan Celleporella hyalina s.l. in the presence and absence of allosperm, and used molecular genetic markers for paternity analysis of progeny to test theoretical predictions that: (1) genets from focal populations with high selfing rates show less inbreeding depression than from focal populations with low selfing rates; (2) genets whose selfed progeny show inbreeding depression prefer outcross sperm (allosperm); and (3) genets bias sex allocation toward female function when reared in reproductive isolation. Offspring survivorship and paternity analysis were used to estimate levels of inbreeding depression and preference for outcrossing or selfing. Sex allocation was assessed by counting male and female zooids. As predicted, inbreeding depression was severe in selfed progeny of genets derived from the populations with low self-compatibility rates, but, with one exception, was not detected in selfed progeny of genets derived from the populations with higher self-compatibility rates. Also, as predicted, genets whose selfed progeny showed inbreeding depression preferred outcrossing, and a genet whose selfed progeny did not show inbreeding depression preferred selfing. Contrary to prediction, sex allocation in the majority of genets was not influenced by reproductive isolation. Lack of economy of male function may reflect the over-riding influence of allosperm-competition in typically dense breeding populations offering good opportunity for outcrossing. We suggest that hermaphroditism may be a plesiomorphic character of the crown group Bryozoa, prevented by phylogenetic constraint from being replaced by gonochorism and therefore not necessarily adaptive in all extant clades. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 519–531. [ABSTRACT FROM AUTHOR]

Adaptive radiation occurs when divergent natural selection in different environments leads to phenotypic differentiation. The pleiotropic effects of underlying genes can either promote or constrain this diversification. Identifying the pleiotropic effects of genes responsible for divergent traits, and testing how the environment influences these effects, can therefore help to provide an understanding of how ecology drives evolutionary change between populations. Positive selection on low-armor alleles at the Ectodysplasin ( Eda) locus in threespine stickleback has led to the repeated evolution of reduced armor in populations following freshwater colonization by fully armored marine sticklebacks. Here, we demonstrate that Eda has environmentally determined pleiotropic effects on armor and growth. When raised in freshwater, reduced armor sticklebacks carrying “low” alleles at Eda had increased growth rate relative to fully armored sticklebacks carrying “complete” alleles. In saltwater treatments this growth advantage was present during juvenile growth but lost during adult growth, suggesting that in this environment stickleback are able to develop full armor plates without sacrificing overall growth rate. The environment specific pleiotropic effects of Eda demonstrate that ecological factors can mediate the influence of genetic architecture in driving phenotypic evolution. Furthermore, because size is important for mate choice in stickleback, the growth rate differences influenced by Eda may have effects on reproductive isolation between marine and freshwater populations. [ABSTRACT FROM AUTHOR]

Increase in seawater temperature is one of the major effects of global climate change that affects marine organisms, including Cnidaria. Among them, gorgonians from the NW Mediterranean Sea, such as the species Eunicella singularis, have suffered spectacular and extensive damage. We thus investigated in a controlled laboratory experiment the response of E. singularis to a long-term increase in temperature and we took a special interest in its photosynthetic and calcification response to the stress. Two populations collected at 15 and 35m depths were studied in order to determine whether there was a difference in sensitivity to thermal stress between living depths. Our results show: (a) that calcification and photosynthesis were impacted only when gorgonians were maintained for more than two weeks at 26°C, and (b) that colonies of E. singularis living in shallow waters were less tolerant than those living in deep waters. Because E. singularis is a symbiotic species, we have also discussed the potential role of symbiosis in the thermotolerance response. [ABSTRACT FROM AUTHOR]

Aim The Pleistocene glaciations were the most significant historical event during the evolutionary life span of most extant species. However, little is known about the consequences of these climate changes for the distribution and demography of marine animals of the north-eastern Atlantic. The present study focuses on the phylogeographic and demographic patterns of the sand goby, Pomatoschistus minutus (Teleostei: Gobiidae), a small marine demersal fish. Location North-eastern Atlantic, Mediterranean, Irish, North and Baltic seas. Methods Analysis was carried out by sequencing the mtDNA cytochrome b gene of sand gobies from 12 localities throughout the species’ range, and using this information in combination with published data of allozyme markers and mtDNA control region sequences. Several phylogenetic methods and a network analysis were used to explore the phylogeographic pattern. The historical demography of P. minutus was studied through a mismatch analysis and a Bayesian skyline plot. Results Reciprocal monophyly was found between a Mediterranean Sea (MS) clade and an Atlantic Ocean (AO) clade, both with a Middle Pleistocene origin. The AO Clade contains two evolutionary significant units (ESUs): the Iberian Peninsula (IB) Group and the North Atlantic (NA) Group. These two groups diverged during Middle Pleistocene glacial cycles. For the NA Group there is evidence for geographic sorting of the ancestral haplotypes with recent radiations in the Baltic Sea, Irish Sea, North Sea and Bay of Biscay. The demographic histories of the Mediterranean Clade and the two Atlantic ESUs were influenced mainly by expansions dated as occurring during the Middle Pleistocene glaciations and post-Eem, respectively. Main conclusions The pre-LGM (Last Glacial Maximum) subdivision signals were not erased for P. minutus during the LGM. Middle Pleistocene glaciations yielded isolated and differently evolving sets of populations. In contrast to the case for most other taxa, only the northern Atlantic group contributed to the post-glacial recolonization. The historical demography of Mediterranean sand gobies was influenced mainly by Middle Pleistocene glaciations, in contrast to that of the Atlantic populations, which was shaped by Late Pleistocene expansions. [ABSTRACT FROM AUTHOR]

Mudskippers (Gobiidae: Oxudercinae) are amphibious gobies. The occurrence and habitats of seven sympatric species of Malayan mudskippers were recorded: Boleophthalmus boddarti, Boleophthalmus pectinirostris, Periophthalmodon schlosseri, Periophthalmus chrysospilos, Periophthalmus gracilis, Periophthalmus variabilis and Scartelaos histophorus. A total of 14 surveys were made at six localities along 120 km of the west coast of the Malay Peninsula in August 1996 and September 2006. A multivariate set of ordinal parameters were used to measure the quantity of environmental water in mudskippers’ habitats, and three guilds of species were discriminated. The resulting pattern mirrored the adaptive scenario depicted by physiological and anatomical studies of mudskippers’ terrestriality, although in one case a terminal taxon was less terrestrial than other more basal ones. Differentiation of trophic niches may also play a role in habitat selection by the herbivorous Boleophthalmus spp., which were only found in unvegetated, illuminated areas and on wet mud at low tide. With the more terrestrial guild, a significant negative co-occurrence suggested direct interspecific competition. [ABSTRACT FROM AUTHOR]

Both habitat preferences and social organization can influence the spatial distributions of individuals. We explored effects of individual behavior and social organization on distributions of arc-eye hawkfish ( Paracirrhites arcatus) in lagoons of French Polynesia. Analysis of habitat selectivity data obtained during surveys revealed that the most highly preferred microhabitat of arc-eye hawkfish was large Pocillopora coral with an open branching morphology. However, such corals were rare and most hawkfish occupied smaller, less preferred Pocillopora. Indeed, total abundance of Pocillopora explained nearly two thirds of the lagoon-wide variation in abundance of hawkfish and the derived relationship between the numbers of hawkfish and Pocillopora predicted 86% of the spatial variation in hawkfish abundance during subsequent surveys. In contrast, large, open-branched Pocillopora explained little of the spatial variation in abundance of hawkfish. Individual behavior and social organization significantly impacted use of the most highly preferred Pocillopora. During a colonization experiment set up outside hawkfish home ranges, all colonizers resided on the most highly preferred corals. Following addition of the most highly preferred Pocillopora corals to areas occupied by hawkfish, only the largest, socially dominant individuals obtained access to added corals, spending significantly more time and increasing both aggressive acts and prey attacks from these substrates. These results illustrate the importance of understanding the modulating effects of social behavior on habitat use and explain why most hawkfish individuals do not occupy their most preferred microhabitat type. [ABSTRACT FROM AUTHOR]

The local flow environment affects the shape of waterborne chemical signals through a variety of physical mechanisms and at several scales. Since crayfish rely on these chemical signals to extract information about predators, prey, and mates, one might expect the chemical sensors (aesthetascs) on crayfish antennules to be physically tuned to the presentation of chemical cues by the flow environment. This hypothesis was tested by comparing length, diameter, and spacing of antennules and aesthetascs among geographically distinct populations of Orconectes virilis. Crayfish were collected from the Chagrin river, Hebron hatchery, and Burt lake. In addition, antennules were sampled from 43 museum populations representing 12 lake, 10 creek, and 21 river populations from multiple states and river drainages. Mean velocities from the collection sites were either measured directly or calculated from United States Geological Survey (USGS) historical data. Structural parameters were measured using Scion Image software on Scanning electron microscope micrographs, and analyses of variance were performed using StatView. Structural parameters of aesthetascs were found to vary with flow environment. Aesthetascs from lake populations were inserted at a larger angle, extended out farther from the supporting antennule relative to the width of the antennule, and were more widely spaced than aesthetascs from creek, hatchery, and river populations. [ABSTRACT FROM AUTHOR]

Synopsis Bryozoans are suspension feeding colonial animals that remain attached to the substratum or other surfaces. How well a bryozoan can feed in a particular flow regime could help determine the distribution and abundance of that bryozoan. I tested how velocity of flow affects feeding rate in four species of bryozoans in the laboratory and how these species perform in different flow regimes in the field. I found that one species, Membranipora membranacea, had a higher ingestion rate than did the other three species at all velocities of flow tested. Membranipora also had a higher rate of ingestion at intermediate velocities, while velocity did not have as strong an effect on ingestion rate in the other three species. As predicted from the feeding experiments, all four species generally had greater abundance, attained a larger size, grew faster, and survived longer in flow regimes in which feeding is higher. Also as predicted, Membranipora had greater abundance, attained a larger size, grew faster, and survived longer than did the other three species both in slower and faster flow regimes in the field. Understanding how flow affects feeding can help predict the distribution and abundance of bryozoans in the field. Because especially efficient filterers like Membranipora can grow faster and have higher survival under a wide range of conditions of flow, this species may be able to outcompete many other species or take advantage of ephemeral habitats, thereby becoming a potentially effective invasive species as has been seen in the Gulf of Maine. [ABSTRACT FROM AUTHOR]

Warming of the planet has accelerated in recent years and is predicted to continue over the next 50 to 100 yr. Evidence of responses to present warming in marine ecosystems include shifts in the geographic range of species as well as in the composition of pelagic and demersal fish, benthic, and intertidal assemblages. Here we provide a review of the changes in geographic distributions and population abundance of species detected on rocky shores of the NE Atlantic over the last 60 yr. This period encompassed the warm 1950s, a Colder period between 1963 and the late 1980s and the recent period of accelerating warming to levels above those of the 1950s. The likely consequences of these responses are then explored. To do this, a summary of the dynamic balance between grazers, macroalgae and barnacles in structuring mid-shore communities is given before outlining experimental work on interactions between key components of rocky shore communities. Modelling and quantitative forecasting were used to predict changes in community composition and dynamics in a warmer world and their consequences for ecosystem functioning discussed. We then identify areas that need further work before making a case for the use of rocky shore species not just as inexpensive indicators of change offshore, but as tractable models to explore the direct and indirect effects of climate change in marine and coastal ecosystems. We also provide a societal perspective emphasising the value of long-term studies in informing adaptation to climate change. [ABSTRACT FROM AUTHOR]

The article focuses on a study on benthic invertebrates performed at the estuary of Capibaribe River, Recife, northeast of Brazil. Researchers found male crab Aratus pisonii infected, showing one externa of Loxothylacus panopaei. They claimed that adult parasites of the species were a hyperosmotic regulator at salinities and concluded that the parasite was perfectly adapted to the environment.