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Where biodiversity conservation and environmental preservation are significant concerns, rapid assessment and monitoring of the colonization and spread of non-native species are essential for timely decision-making and response. We developed and evaluated the adequacy of a rapid assessment protocol (RAP) for detecting non-native fish species in 74 Eastern Brazilian lakes. The RAP consists of a single field day employing two surveyors to conduct interviews with local sport fishers, visual surveys of fish, angling with lures, and gillnetting. We compared our results with those from separate, intense, large sampling effort (LSE) field surveys. Despite requiring less than 1/100th of the field effort, the RAP was able to detect the presence of most non-native fish species that were reported in the same lakes by LSE surveys. Information from local sport fishers was invaluable, particularly for detecting species that were in low abundance, but was not available for lakes within a forest preserve area. Non-native introductions commonly lead to rapid and widespread invasion and adverse effects on native biota. Our results strongly suggest that the RAP could function as a cost-effective tool for efficiently assessing the presence of non-native fishes in lakes and monitoring their colonization and spread over large geographic areas. [ABSTRACT FROM AUTHOR]

The Neotropical region has the greatest taxonomic and functional diversity of fish in the world. However, this biodiversity has been threatened by the introduction of non-native species. Therefore, we present a systematic review of the literature concerning the introduction of non-native fish species in Neotropical freshwaters. We examine the origins of non-native fish species, as well as the invaded ecoregions and introduction vectors. Oncorhynchus mykiss, Salmo trutta, Cichla kelberi, and Oreochromis niloticus were the most frequent introduced fish species and rivers and reservoirs were the most studied freshwater ecosystems. Impoundments, aquarium trade, sport fishing, and aquaculture were recorded as the main vectors for the introduction of non-native fish species. Most of the studies were conducted in Brazil. The Upper Parana ecoregion exhibited the largest number of non-native fish species, of which the majority originated from the Lower Parana ecoregion. We noticed that the origins of non-native fish species are linked to their introduction vectors, as several non-native fish species arrive from areas near to where they are introduced, mainly by impoundment and sport fishing. On the other hand, species from regions outside the Neotropics are especially introduced by aquarium trade and aquaculture. [ABSTRACT FROM AUTHOR]

Non-native species are often major drivers of the deterioration of natural ecosystems. The common carp Cyprinus carpio are known to cause major changes in lentic systems, but may not be solely responsible for large scale changes in these ecosystems. We used data from extensive collection efforts to gain insight into the importance of carp as drivers of ecosystem change in Lake Patzcuaro, Mexico. We compared the structure (fish density, biomass, diversity, and evenness) of fish assemblages from six Lake Patzcuaro sites with different habitat characteristics. Intersite comparisons were carried out for both wet and dry seasons. We explored the relationships between non-carp species and carp; and studied multivariate interactions between fish abundance and habitat characteristics. From a biomass perspective, carp was dominant in only four of six sites. In terms of density, carp was not a dominant species in all sites. Further, carp density and biomass were not negatively related to native species density and biomass, even when carp density and biomass were positively correlated to water turbidity levels. Carp dominated fish assemblages in the shallowest sites with the highest water turbidity, plant detritus at the bottom, and floating macrophytes covering the lake surface. These results suggest that the effect of carp on fish assemblages may be highly dependent on habitat characteristics in Lake Patzcuaro. Watershed degradation, pollution, water level loss, and other sources of anthropogenic influence may be more important drivers of Lake Patzcuaro degradation than the abundance of carp. [ABSTRACT FROM AUTHOR]

We examined the interactions of the common carp ( Cyprinus carpio L.) and nutrient additions on water quality, sedimentation rates, and submerged macrophyte biomass in mesocosms in Delta Marsh, Manitoba, Canada. We wanted to determine if carp and nutrients interacted synergistically to increase phytoplankton biomass. A two-by-three duplicated, factorial design had the following treatments: (1) control mesocosms with no carp or nutrient additions; (2) low carp density and no nutrient additions; (3) high carp density and no nutrient additions; (4) no carp and nutrient additions; (5) low carp density and nutrient additions; and (6) high carp density and nutrient additions. The presence of carp increased ammonia concentrations, turbidity, and phytoplankton biomass as expected but did not increase total reactive phosphorus concentrations. The presence of carp did not appear to interact synergistically with nutrient additions to increase phytoplankton as has been suggested by others. In mesocosms with high carp density and receiving nutrient enrichment, phytoplankton appeared to be suppressed relative to mesocosms receiving nutrient enrichment only, and nutrient enrichment and low carp density. Overall, the presence of carp appears to mimic the effects of eutrophication. Our results demonstrate that carp can cause a shift from a clear, macrophyte-dominated state to a turbid phytoplankton-dominated state at a biomass of less than 600 kg ha. [ABSTRACT FROM AUTHOR]

The axolotl ( Ambystoma mexicanum) is a critically endangered and threatened species endemic of the Central Valley of Mexico. The population of this neotenic amphibian has declined in recent years as a result of habitat destruction, polluted waters, and the introduction of exotic species such as tilapia. We evaluated the antipredator response of predator-naïve axolotls to visual and chemical cues of the Nile tilapia ( Oreochromis niloticus) and its foraging consequences. Axolotls decreased their activity and increased their use of refuge in the presence of combined chemical and visual cues from the predator. The axolotls seem to use their vision to confirm the level of risk perceived through chemical signals to modulate their antipredator response accordingly. The axolotls engaged in prey capture at a similar rate independent of the type of predator exposure. However, the efficiency of prey capture decreased in axolotls exposed to the chemical and the combined visual and chemical cues from the tilapia. The foraging costs to the axolotls induced by tilapia can ultimately affect their growth rate and size. The axolotls display antipredator behaviours to reduce the risk of predation by tilapia, which is a primary condition of coexistence with this exotic predator. [ABSTRACT FROM AUTHOR]

The alteration of aquatic ecosystems and increasing aquarium fish trade with exotic species is promoting the presence and invasion of these species in large river systems, with the consequent loss of native biodiversity and the homogenization of aquatic systems. The Chontalcuatlan-Amacuzac hydrological system belonging to the biogeographical province of the Balsas River is one of the main regions in Mexico devoted to the breeding and rearing of aquarium fish, where the improper handling of these organisms has caused their escape to adjacent hydrological systems and, together with urban and industrial pollution, are changing schemas and levels of regional biodiversity. As a first approximation to determine these effects, we evaluate a segment of 140 km of this hydrological system through surveys in 12 sites during the time of major climatic and flow stability, and relating environmental variables with the distribution and abundance of fish. Also, the structure of fish assemblages was assessed by means of similarity and multivariate statistical methods (correspondence and principal components analysis), and these assemblages were found to be segregated by a thermal gradient. Exotic fish were dominant in conditions of low environmental quality, while native species were restricted to areas with better quality of water and geographic isolation. Exotic taxa such as Amatitlania nigrofasciata, Pterigloplictys disjunctivus, Pterigloplictys pardalis, Poeciliopsis gracilis and Heterandria bimaculata, have achieved the degree of invasive due to the fact that they are distributed of abundant manner in the entire hydrological system. [ABSTRACT FROM AUTHOR]

An empirical study was conducted on the effects of an introduced predator-prey pair, largemouth bass and bluegill, on pelagic productivity in 22 ponds in central Japan. In the univariate analysis, the effect of fish invasion on chlorophyll concentration was not evident, primarily because this effect was screened by the positive and negative effects of phosphorus availability and the pond area, respectively. A positive effect on chlorophyll concentration was detected in the best statistical model using nutrient availability and pond area as independent factors. Fish invasion decreased the relative biomass of crustaceans to rotifers. This study showed that the invasion of these exotic fishes affected the pelagic community in the pond. [ABSTRACT FROM AUTHOR]

Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake. [ABSTRACT FROM AUTHOR]

We record here the recent occurrence, abundance and distribution of six exotic fish species, viz. Oreochromis mossambicus, Cyprinus carpio, Hypopthalmicthys molitrix, Ctenopharyngodon idellus, Clarias gariepinus, and Pterygoplichthys disjunctivus (a new exotic in India) distributed through the four important tributaries of river Ganga basin in India. From the total catch, the abundance index of all exotic species in different rivers ranged from 1.1 to 14.5 % with highest value in River Gomti. The relative abundance of the exotic species in all the four tributaries demonstrated that a single species C. carpio contributed a considerable abundance (43.3-83 %) than that of the remaining exotic fishes. The Common Carp, C. carpio, was ubiquitous in all the four tributaries of Ganges basin studied and had the highest local distribution (52.63 %). Smaller size groups of endangered ( Chagunius chagunio, Chitala chitala, and Tor tor) and migratory species ( Bagarius bagarius, Ompok pabda, Wallago attu, and Sperata aor) in the four tributaries were recorded, and the increasing appearance of Common Carp and other exotic fishes is signaling biological invasion. Possible threats to the indigenous fish fauna, as a result of the invasion and proliferation of these exotics, are discussed. [ABSTRACT FROM AUTHOR]

Nekton communities were sampled from 38 Hawaiian coastal wetlands from 2007 to 2009 using lift nets, seines, and throw nets in an attempt to increase our understanding of the nekton assemblages that utilize these poorly studied ecosystems. Nekton were dominated by exotic species, primarily poeciliids ( Gambusia affinis, Poecilia spp.) and tilapia. These fish were present in 50-85% of wetlands sampled; densities were up to 15 times greater than native species. High densities of exotic fish were generally found in isolated wetlands with no connection to the ocean, were often the only nekton present, were positively correlated with surface water total dissolved nitrogen, and were negatively correlated with native species richness. Native species were present in wetlands with complete or partial connection to the ocean. Additional studies are needed to document exotic fish impacts on native fish and bird habitat and whether native fish communities can contribute to invasion resistance of coastal wetlands. Future wetland restoration should include exotic fish eradication, maintenance of hydrological connection to the ocean, or programs to prevent future introductions in order to create wetlands that support native-dominated nekton communities. [ABSTRACT FROM AUTHOR]

Food web structure is well known to vary widely among ecosystems. Recent research indicates that there can be a high degree of spatial heterogeneity within ecosystems as well. Xochimilco is a small heterogeneous freshwater system that has been transformed into a network of canals, small lakes, and wetlands. Located within Mexico City, this ecosystem has been intensively managed and highly impacted for more than 50 years. This system receives urban and agricultural runoff, with resulting impacts on water quality. The aquatic community is dominated by exotics such as carp ( Cyprinus carpio) and tilapia ( Oreocrhomis niloticus), though the system still supports endemic species such as the aquatic salamander, axolotl ( Ambystoma mexicanum), and crayfish ( Cambarellus montezumae), which are both endangered. In this study, we used carbon and nitrogen stable isotopes for the whole food web and gut content analysis from the exotic fishes to describe food web structure in different canals within Xochimilco. There were significant isotopic differences among canals. These differences may result from isotopic baseline differences as well as differences in actual food web structure: both are related to local spatial variation in water quality driven by nutrient inputs and exotic fishes. Within-ecosystem variability is likely to be seen in other perturbed shallow systems as well, and should be explicitly considered in future food web studies. [ABSTRACT FROM AUTHOR]

Here we review the thirty year recovery effort and conservation status of the Ozark cavefish, Amblyopsis rosae. We summarized the historic and current range of the species, and report county range extensions for both A. rosae and its confamilial Typhlichthys subterraneus. Ozark cavefish survey data spanning almost a century were analyzed for temporal trends using the Mann-Kendall Test/Sen’s Slope Estimator Method. Results were inconclusive because variance was high and the majority of data sets were not sufficiently large to detect a trend. However, the two largest populations (Cave Springs Cave and Logan Cave, Benton Co., Arkansas) have stabilizing or increasing survey counts. While the number of active cavefish sites has decreased over 50% since 1990, the number of surveyed individuals has not. Reasons for endangerment were reanalyzed since federal listing; the primary threat has shifted from overcollection to habitat degradation. We analyzed the progress of recovery task implementation, and we critically evaluated the basis of delisting criteria. Recovery Task 1, the hydrogeologic delineation of subterranean habitats, is almost complete. Recovery Task 2 prescribes protection and management for Recovery Caves, and important progress has been made. Recovery Task 3 involves the development and implementation of monitoring programs in Recovery Caves. Several important studies have been performed, and indicate that many cavefish populations are experiencing chronic, low-level exposure to a suite of anthropogenic contaminants. Delisting conditions are largely unattainable as currently worded. We suggest that recovery criteria be amended such that habitat protection goals are attainable, that the list of Recovery Caves can be periodically updated, and that the recovery population goal is increased and distributed between more sites. [ABSTRACT FROM AUTHOR]

Rainbow trout introduced into Hokkaido in 1920 have become widely distributed due to extensive release into many reservoirs and lakes for sport-fishing; their presence often results in reductions of native fish populations. We analyzed and predicted the relationship between the probability of occurrence of rainbow trout and the proximity of dams (or attributed reservoirs), using a database of the presence or absence of rainbow trout collected during 1960–2004 in Hokkaido to clarify the spread patterns of exotic species (e.g., rainbow trout) due to large-scale damming over a long period. Rainbow trout were abundant in streams within approximately 10 km of dams in recent years, regardless of whether the stream was up- or down-stream from the dam and after accounting for the effects of other environmental variables (e.g. elevation, population density, and survey year). A delayed increase in trout occurrence below dams as compared with above dams suggests that the occurrence below dams may be largely due to escapement of stocked populations and a continuously increasing abundance since 1970. The management of dams and reservoirs is necessary to prevent further spread of rainbow trout because they can threaten habitats of native Japanese salmonids through various mechanisms. [ABSTRACT FROM AUTHOR]

Roadless areas are important for biodiversity maintenance and nature conservation but remain politically controversial due to conflicting interests of conservation and development. In this study, we applied a recently developed index of roadless volume (RV) across 67 counties of Alabama, USA as a case study to examine the relationships between roadless areas and local species richness. Our results indicated that with the increase of RV across counties, both the number of total fish and exotic fish species increased, but the relationship was not significant for endemic fish species. The number of both herpetofaunal and plant species also increased with the increasing RV. For all included species, there was a significant positive correlation between species richness and RV values. The number of endangered species decreased with the increase of RV per-capita. Wildfire occurrences increased with the increase of RV. Preserving roadless areas is an important component of biodiversity conservation. [ABSTRACT FROM AUTHOR]

The Baja California killifish, Fundulus lima, is found in six desert oases of the southern Baja California Peninsula, Mexico. The recent introduction of exotic fishes, particularly redbelly tilapia, have impacted the ecology of Fundulus lima such that it is now endangered. Plans of relocating F. lima to bodies of freshwater that are free of exotics have been proposed, however little is know about the genetic identity of the current populations. In this study, we examined the mitochondrial control region of F. lima samples from 4 oases, and in addition, compared these samples to their sister species, the California killifish F. parvipinnis. Using a combination of phylogenetic and coalescent approaches, we were able to determine that the two subspecies of the California killifish, F. p. brevis, and F. p. parvipinnis, and F. lima form an unresolved trichotomy that diverged between 200,000 years and 400,000 years ago. The one F. lima individual that we were able to collect in the southernmost oasis grouped with the southern subspecies of the California killifish, F. parvipinnis brevis. In contrast, we found that the 3 northern oases grouped together in a ‘Fundulus lima’ clade. Each oasis is genetically distinct, yet there is no evidence of a marked genetic bottleneck in any populations (Haplotype diversity between 0.5 and 0.8). Future relocation plans will therefore need to be done cautiously to preserve the genetic identity of the original populations. [ABSTRACT FROM AUTHOR]

Competitive interactions between Galaxias maculatus, native to southeastern Australia, and Gambusia holbrooki, an exotic pest, were examined in relation to two types of artificial cover and a food source. Experiments were performed in an 800 l tank using photographic techniques. The relative distance of G. maculatus from cover or food source before and after the introduction of G. holbrooki were compared. Also, the proportions of the species were altered to examine the effects of unequal numbers on dominance behaviour. It was found that G. holbrooki was unable to out compete G. maculatus for either cover or food. The distance of G. maculatus from a food source was seen to increase following the introduction of G. holbrooki, when they outnumbered G. maculatus by 3 to 1. Although the distance from the food of␣ G.␣maculatus increased following the introduction of G. holbrooki, in all cases the mean distance of G.␣maculatus from cover or food was less than that of G. holbrooki. Significant intra-species competition appeared to occur between G. maculatus and it may be that this competition had a greater effect than the competitive pressure G. holbrooki was able to place on the natives. This study revealed that the exotic pest species, G. holbrooki, could not out compete a small native Australian fish species. [ABSTRACT FROM AUTHOR]

The relationship between invasions by two exotic fishes ( Micropterus salmoides and Lepomis macrochirus) and species diversity in native fish communities was studied in 14 Japanese farm ponds. We found that mean number of species in native fish communities was three times higher in the ponds without the exotic fish than in the ponds with them. Further, negative relationships were observed between abundance of the two exotic fish and the total abundance of native fish communities. Our results suggest that invasions by the two exotic fish caused serious depletion of native fish communities, although another process can also be considered , that is, that ponds with poor native fish communities were prone to colonization by these exotic fish. [ABSTRACT FROM AUTHOR]

Lakes of western Victoria are typically shallow (2–3 m), slightly saline (3–8 ppt) and eutrophic (total phosphorus 0.1–5 mg l-1 and total nitrogen 3–8 mg l-1). These lakes are prone to algal blooms in late spring and summer. We conducted experiments in ponds to determine whether lake zooplankton exert enough grazing pressure to control algal blooms and also if carp predation can regulate zooplankton communities and increase algal biomass. Zooplankton grazing (high zooplankton, low zooplankton and control) and carp predation (carp, nutrient and control) experiments had three treatments and each treatment had three replicates. Algal numbers and biomass (28 μg l-1) were uniform in all ponds before zooplankton stocking. When stocked with lake zooplankton, algae were consumed efficiently and after 30 days algal numbers and biomass were significantly lower than those in control ponds (0.4 μg l-1 and 33 μg l-1, respectively). Ponds stocked with low zooplankton numbers were intermediate. Complete elimination of Cladocera and subsequent increase in algal biomass (from 4 to 45 μg l-1) occurred after 30 days in carp treatment ponds. Zooplankton and algal populations were unaffected when nutrients but no carp were added and also in control ponds with no added nutrients or carp. The pond experiments illustrated the mechanics of a carp mediated trophic cascade when stocked with species and densities of zooplankton naturally occurring in lakes of western Victoria. Confirmation of whether this process occurs in turbid Australian lakes is urgently required. [ABSTRACT FROM AUTHOR]

There is little published information on the impacts of exotic fishes in the shallow slightly saline, closed catchment lakes of western Victoria. The present study assessed the diet of exotic carp ( Cyprinus carpio) from two lakes of western Victoria (Lake Colac and Lake Modewarre) between November 1999-September 2001, using a numerical and volumetric method of gut contents analysis. Carp larvae <2 cm total length fed exclusively on microcrustacea (Cladocera and Copepoda). At a mean total length of >2 cm carp larvae shifted their diet to include benthic food resources, but microcrustacea still dominated the larval diet. Small carp (=15 cm) showed a high preference for microcrustacea and tended to avoid benthic macroinvertebrate food resources. As carp size increased the proportion of macroinvertebrates in gut contents increased. Medium (15?40 cm) and large sized carp (>40 cm) displayed broad food assemblages in their guts with microcrustacea, Gastropoda, Ostracoda, Amphipoda and detritus being dominant. Carp showed a selective preference for Diptera and a balanced preference for Amphipoda. Schoener's dietary overlap was high between small and medium carp (0.55?0.65) and medium and large carp (0.72?0.74) but was low between small and large carp (0.36?0.44). When considering only benthic macroinvertebrate food resources, Hurlbert's dietary overlap between size classes of carp remained reasonably low. There were no observable seasonal patterns in the diet of carp in the two lakes but the proportion of the food items in the gut varied between sampling occasions. This study identified the potential of exotic carp in altering lake function by feeding predominantly on microcrustacea, thus causing a 'top-down' trophic cascade. [ABSTRACT FROM AUTHOR]

In floodplain ponds with low piscivore abundance, both endemic Midgley's gudgeons, Hypseleotris sp. 5, and exotic mosquitofish, Gambusia holbrooki, showed significant ontogenetic variation in the use of food and space. Small gudgeons were generally associated with surface and benthic habitats, then restricted their distribution to benthic habitats at a size of approximately 24 mm (standard length). The ontogenetic variation in mosquitofish habitat use was less discrete, and could be described as a tendency for larger individuals to be associated with the bottom of the littoral macrophyte beds than with the surface of the macrophyte beds or surface of the limnetic zone. Small gudgeons exhibited high spatial overlap with mosquitofish within the surface habitats of the ponds. All size-class/species comparisons showed significant partitioning of food resources, however, the diets of small gudgeons and mosquitofish were very similar. Therefore, juvenile gudgeons may have to pass through a similar spatial and trophic niche to introduced mosquitofish before recruiting to the adult stage. Possible mechanisms driving the ontogenetic variation in gudgeon and mosquitofish habitat use are discussed. This paper demonstrates that ontogenetic niche shifts at fine spatial scales can affect our interpretation of interactions between native and introduced fishes. [ABSTRACT FROM AUTHOR]

We summarized data from eight quantitative fish surveys conducted in southern Florida to evaluate the distribution and relative abundance of introduced fishes across a variety of habitats. These surveys encompassed marsh and canal habitats throughout most of the Everglades region, including the mangrove fringe of Florida Bay. Two studies provided systematically collected density information over a 20-year period, and documented the first local appearance of four introduced fishes based on their repeated absence in prior surveys. Those species displayed a pattern of rapid population growth followed by decline, then persistence at lower densities. Estuarine areas in the southern Everglades, characterized by natural tidal creeks surrounded by mangrove-dominated marshes, and canals held the largest introduced-fish populations. Introduced fishes were also common, at times exceeding 50% of the fish community, in solution holes that serve as dry-season refuges in short-hydroperiod rockland habitats of the eastern Everglades. Wet prairies and alligator ponds distant from canals generally held few individuals of introduced fishes. These patterns suggest that the introduced fishes in southern Florida at present may not be well-adapted to persist in freshwater marshes of the Everglades, possibly because of an interaction of periodic cold-temperature stress and hydrologic fluctuation. Our analyses indicated low densities of these fishes in central or northern Everglades wet-prairie communities, and, in the absence of experimental data, little evidence of biotic effects in this spatially extensive habitat. There is no guarantee that this condition will be maintained, especially under the cumulative effects of future invasions or environmental change. [ABSTRACT FROM AUTHOR]

Japanese freshwater fishes, including lampreys. comprise 15 orders, 35 families, and 96 genera, with 211 species and subspecies. Most belong to the families Cyprinidac (29% of species and subspecies), Gobiidae (21%), Salmonidae (1.0%), and Cobitidae (8%). Cyprinids and cobitids presumably originated from east Asia, gobiids from southeast Asia, and cottids and salmonids from the north Pacific. Japanese freshwater fishes include 88 endemic species and subspecies, of which three have been extirpated. Fishes introduced into natural rivers and lakes for inland commercial fisheries and sport fishing, and by accident, include many exotic species, of which 23 now inhabit natural freshwaters. These often have destroyed the local fish fauna by predation, and caused genetic pollution by hybridization with local strains. Destruction of freshwater environments by land development also poses a threat to Japanese freshwater fish communities. In addition Japanese freshwater systems have been markedly altered by development of rice paddy fields which have caused some species to decline but others to flourish, and changed the distribution patterns of fishes between upstream and down-stream areas. To conserve endangered species and declining communities of Japanese freshwater fishes, we need to clarify the characteristics of their original habitats and the effects of developing paddy fields, from both the ecological and historical points of view. [ABSTRACT FROM AUTHOR]

The article offers information about the exotic fish Misgurnus fossilis (Cobitidae) which is native to Europe. It notes that the number of this species decreased, specifically in central Europe. It also has low level genetic diversity within the whole area of its spread which may increase its habitat change vulnerability.

This article presents information about Zoogoneticus tequila, one of the threatened fishes of the world. Its common name is Picote de Tequila. Adult male size is 28.2 to 10mm SL with cream-colored terminal bands in the dorsal, anal and pelvic fins of adult males. It is distinguished from its only congeneric species, Zoogoneticus quitzeoensis, by a prominent subterminal crescent-shaped orange-yellow band in the caudal fin of males. The species is matrotrophic; embryos develop in the cavity of the single, median ovary. It faces several threats which includes habitat fragmentation, introduction of exotics and intensive collection by specialized aquarium hobbyists and academics.

The article presents information on a fish species fundulus lima that is an endangered species. Its common names are Baja killifish, San Ignacio killifish and Sardinita peninsular. Although, there are no quantitative evaluations of the abundance of this species before the introduction of exotic fishes to the oases, current monitoring along its historic range has revealed low relative abundance of this native killifish as compared to exotic species. Since this killifish is one of only three known freshwater taxa endemic to Baja California peninsula, its very limited distribution merits considetarion at least as threatened.