The Southeastern Fishes Council Technical Advisory Committee reviewed the diversity, distribution, and status of all native freshwater and diadromous fishes across 51 major drainage units of the southern United States. The southern United States supports more native fishes than any area of comparable size on the North American continent north of Mexico, but also has a high proportion of its fishes in need of conservation action. The review included 662 native freshwater and diadromous fishes and 24 marine fishes that are significant components of freshwater ecosystems. Of this total, 560 described, freshwater fish species are documented, and 49 undescribed species are included provisionally pending formal description. Described subspecies (86) are recognized within 43 species, 6 fishes have undescribed subspecies, and 9 others are recognized as complexes of undescribed taxa. Extinct, endangered, threatened, or vulnerable status is recognized for 28% (187 taxa) of southern freshwater and diadromous fishes. To date, 3 southern fishes are known to be extinct throughout their ranges, 2 are extirpated from the study region, and 2 others may be extinct. Of the extant southern fishes, 41 (6%) are regarded as endangered, 46 (7%) are regarded as threatened, and 101 (15%) are regarded as vulnerable. Five marine fishes that frequent fresh water are regarded as vulnerable. Our assessment represents a 75% increase in jeopardized southern fishes since 1989 and a 125% increase in 20 years. The trend for fishes in the southern United States is clear; jeopardized fishes are successively being moved from the vulnerable category to that of imminent threat of extinction.
African Americans and other ethnic minorities are severely underrepresented in both graduate education and among the professoriate in ecology and evolutionary biology (EEB). In the present research, we take a social psychological approach to studying inclusion by examining interrelationships among challenges to inclusion, the sense of belonging, and interest in pursuing graduate education in EEB. We conducted a survey of African American (N = 360), Latino/a/Hispanic (N = 313), White (N = 709), and Asian/Asian American (N = 524) college undergraduates majoring in science, technology, engineering, and math fields and used the results to test several interrelated hypotheses derived from our theoretical model. Compared to Whites, ethnic minorities were more likely to experience challenges to inclusion in EEB (e.g., less exposure to ecology, fewer same-race role models, discomfort in outdoor environments). Challenges to inclusion were associated with a decreased sense of belonging in EEB educational contexts. Finally, experiencing a low sense of belonging in EEB educational contexts was associated with lower interest in pursuing graduate education in EEB. Sense of belonging in EEB was especially low among African Americans relative to Whites. We discuss the implications of the study results for educational interventions.
We analysed mitochondrial genomic sequences under maximum likelihood (ML) criteria to explore phylogenetic relationships, and performed historical biogeography analysis with divergence time estimation for fishes of Order Cypriniformes (Actinopterygii: Ostariophysi). We added mitogenomes for eight new cypriniforms and one outgroup to a data set comprising 53 and six outgroup mitogenomes from a previous study to make our taxon sampling geographically representative. The ML tree reconfirmed monophyly of four basal cypriniform clades (cyprinids, catostomids, gyrinocheilids, and loaches including balitorids and cobitids). It also recovered 18 monophyletic groups largely equivalent to the subfamilial rank, and resolved interrelationships among most of these subfamilial clades. However, lower bootstrap support for the ML tree and higher approximately unbiased (au) probabilities for alternative topologies around some branches indicated problems that still need to be resolved. Historical taxon biogeography by dispersal-vicariance analysis, a parsimonious reconstruction of past ranges, and gain-loss ratio analysis at the subfamilial level, identified the geographical region of basal cypriniform divergence as southern Asia. Bayesian divergence time analysis dated the basal otophysan split, which gave birth to Order Cypriniformes, to the late Triassic around 219.5 Mya. The basal cypriniform divergence took place during the late Jurassic around 155.9 Mya. These dates coincide with the onset and completion, respectively, of the Pangaean breakup. Taking biogeographical analysis and node dating into account, we consider the most likely candidate for the initial geographical range of Order Cypriniformes to be the south-eastern area of Mesozoic Laurasia (present-day southern Asia, excluding the Indian subcontinent). We also briefly discuss ecological implications of the group's divergence.
The phylogenetics and taxonomic status of small African barbs (Cyprininae: Smiliogastrini) remains unresolved despite the recent decision to elevate the genus name Enteromius for the group. The main barrier to understanding the origin of African small barbs and evolutionary relationships within the group is the poor resolution of phylogenies published to date. These phylogenies usually rely on mitochondrial markers and have limited taxon sampling. Here we investigate the phylogenetic relationships of small barbs of Kenya utilizing cytochrome b, Growth Hormone (GH) intron 2, and RAG1 markers from multiple populations of many species in the region. This multi-locus study produced well-supported phylogenies and revealed additional issues that complicate understanding the relationships among East African barbs. We observed widespread mtDNA introgression within the Kenyan barbs, highlighting the need to include nuclear markers in phylogenetic studies of the group. The GH intron 2 resolved heterospecific individuals and aided in inferring the species level phylogeny. The study reveals unrecognized diversity within the group, including within species reported to occur throughout East Africa, and it provides the groundwork for future taxonomic work in the region and across Africa.
Abstract– Historical and contemporary fish collections were used to examine the influence of agricultural land use on fish communities in the central Chattahoochee River, USA. In‐stream habitat data were also collected to examine the relationship between agricultural land use and stream habitat structure. We found a significant positive relationship between agricultural land use and in‐stream sediment (r2=0.43, P=0.01). Stream depth heterogeneity decreased significantly with increased sediment (r2=0.39, P=0.02). Mainstream reaches draining agricultural lands had significantly lower levels of fish diversity than forested reaches (r2=0.47, P < 0.01). Agriculture also explained significant variation in mainstream species abundances but was not a significant predictor of species diversity or species abundances in headwater reaches. Most pool species that use coarse substrates decreased in relative abundance with increasing agriculture in the watershed. Our results suggest that mainstream environments and their associated communities are more susceptible than headwater reaches to the effects of agriculture. This finding has important consequences for conservation, since mainstream reaches are reported to function as species refugia during pulse disturbance events (e. g., floods, droughts).
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