Robert C. Cashner

Diversity, Distribution, and Conservation Status of the Native Freshwater Fishes of the Southern United States

Abstract 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 diadromou...

Stability and Persistence of Fish Faunas and Assemblages in Three Midwestern Streams

Long term stability of summer fish assemblages was examined in three distinct systems: Piney Creek, a medium-sized Ozark upland tributary of the White River, Arkansas; Brier Creek, a small prairie-margin stream, tributary to the Red River, Oklahoma; and the Kiamichi River, a medium-sized river in the Ouachita Uplands draining into the Red River, Oklahoma. Sampling periods and numbers of surveys of the three stream systems were 14 yr and six collections for Piney Creek, 17 yr and five surveys for Brier Creek, and 5 yr and three surveys for the Kiamichi River. The fish faunas of all three streams were persistent (regarding presence-absence of species). In all three streams overall faunal structure was stable, as indicated by similarity indices and by concordance of rank abundance of the common species in each stream across all collection years. The results corroborated a conclusion from earlier work that the total fish fauna is more stable in a more environmentally benign stream (Piney Creek) than in a stream subject to greater environmental extremes (Brier Creek). The fish fauna of the Kiamichi River was also stable across three survey periods with respect to rank order of species abundance. Stability of the fish assemblages at individual locations on all three streams was variable, but four of five locations on Brier Creek, and all five locations on Piney Creek exhibited significant concordance overall in ranks of species abundance. Of 59 possible cases, assemblages at 27 individual locations (=46%) on the three streams showed assemblage stability >0.60 between survey periods. We conclude that at the level of whole-stream faunas, all three of these midwestern streams were stable across the survey years, and that many, but not all, individual locations had relatively stable fish assemblages.

Fish assemblage stability over fifty years in the Lake Pontchartrain Estuary; Comparisons among habitats using canonical correspondence analysis

We assessed fish assemblage stability over the last half century in Lake Pontchartrain, an environmentally degraded oligohaline estuary in southeastern Louisiana. Because assemblage instability over time has been consistently associated with severe habitat degradation, we attempted to determine whether fish assemblages in demersal, nearshore, and pelagic habitats exhibited change that was unrelated to natural fluctuations in environmental variables (e.g., assemblage changes between wet and dry periods). Collection data from three gear types (trawl, beach seine, and gill nets) and monthly environmental data (salinity, temperature, and Secchi depth) were compared for four collecting periods: 1954 (dry period), 1978 (wet period), 1996–1998 (wet period), and 1998–2000 (dry period). Canonical correspondence analysis (CCA) revealed that although the three environmental variables were significantly associated with the distribution and abundance patterns of fish assemblages in all habitats (with the exception of Secchi depth for pelagic samples), most fish assemblage change occurred among sampling periods (i.e., along a temporal gradient unrelated to changing environmental variables). Assemblage instability was the most pronounced for fishes collected by trawls from demersal habitats. A marked lack of cyclicity in the trawl data CCA diagram indicated a shift away from a baseline demersal assemblage of 50 yr ago. Centroid positions for the five most collected species indicated that three benthic fishes, Atlantic croaker (Micropogonias undulatus), spot (Leiostomus xanthurus), and hardhead catfish (Arius felis), were more dominant in past demersal assemblages (1954 and 1978). A different situation was shown for planktivorous species collected by trawls with bay anchovy (Anchoa mitchilli) becoming more dominant in recent assemblage and Gulf menhaden (Brevoortia patromus) remaining equally represented in assemblages over time. Changes in fish assemblages from nearshore (beach seine) and pelagic (gill net) habitats were more closely related to environmental fluctuations, though the CCA for beach seine data also indicated a decrease in the dominance ofM. undulatus and an increase in the proportion ofA. mitchilli over time. The reduced assemblage role of benthic fishes and the marked assemblage change indicated by trawl data suggest that over the last half century demersal habitats in Lake Pontchartrain have been impacted more by multiple anthropogenic stressors than nearshore or pelagic habitats.

A Discriminant Functions Analysis of Sunfish (Lepomis) Food Habits and Feeding Niche Segregation in the Lake Pontchartrain, Louisiana Estuary

Abstract The food habits of four species of sunfish, Lepomis macrochirus, L. microlophus, L. punctatus, and L. gulosus were studied in the Lake Pontchartrain estuary. Forty estuarine food items were identified from stomach samples. Although the food items were different from those of Lepomis spp. in fresh water, specific feeding patterns in regard to prey size and space partitioning were comparable. A discriminant functions analysis was used to objectively compare specific differences in stomach content data. Differences in discriminant function scores appeared to be due to interspecific feeding niche segregation.

Biochemical Systematics of the Notropis roseipinnis Complex (Cyprinidae: Subgenus Lythrurus)

Ce complexe renferme 4 taxas distribues dans le sud-est des Etats-Unis: Notropis roseipinnis, N. atrapiculus, N.b. bellus, N.b. alegnotus

Notropis suttkusi, a New Cyprinid from the Ouachita Uplands of Oklahoma and Arkansas, with Comments on the Status of Ozarkian Populations of N. rubellus

A new species of cyprinid, Notropis suttkusi, the rocky shiner, is described from tributaries of the Red River draining the Ouachita Uplands in Oklahoma and Arkansas. The geographic range of N. suttkusi extends from the Blue River in Oklahoma eastward to the Cossatot River in Arkansas. It is found primarily in the upper portions of these rivers, and prefers clear water flowing over gravel and rubble substrates. The rocky shiner is compared to populations of the rosyface shiner, Notropis rubellus, from the adjacent Ozark Uplands and east of the Mississippi River, from which it can be distinguished by its deeper and more robust body form; shorter snout and upper jaw; denser pigmentation on scales, lips, and gular region; finer tubercles on the snout; greater extent of lateral band; and more deeply decurved lateral line. A brief discussion of the confusing taxonomic history involving N. atherinoides, N. oligaspis, N. percobromus, and N. rubellus is presented.

Fundulus bifax, a New Species of the Subgenus Xenisma from the Tallapoosa and Coosa River Systems of Alabama and Georgia

fishes from the eastern tropical Atlantic. Jap. J. Ichthy. 33(3):213-222. LEVITON, A. E., R. H. GIBBS, JR., E. HEAL AND C. E. DAWSON. 1985. Standards in herpetology and ichthyology: part I. Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Copeia 1985:802-832. OGILBY,J. D. 1888. Notes and exhibits [remarks on Anthias (Pseudanthias) cichlops.] Proc. Linn. Soc. N.S.W., Ser. 2, 3(2):741. RANDALL,J. E., AND G. R. ALLEN. 1978. Anthias pictilis, a new serranid fish from the subtropical southwestern Pacific. Rev. Fr. Aquariol. 5(2):33-36. SMITH, J. L. B. 1955. The fishes of the family Ano and T. Yoshino (eds.). Tokai University ss, Tokyo, Japan. thiidae of the western Indian Ocean. Ann. Mag. Nat. Hist., Ser. 12, 8:337-350. . 1961. Fishes of the family Anthiidae from the western Indian Ocean and the Red Sea. Ichthy. Bull., Dept. Ichthy., Rhodes Univ. 21:359-369. SNYDER, J. 0. 1911. Descriptions of new genera and species of fishes fromJapan and the Riu Kiu Islands. Proc. U.S. Nat. Mus. 40:525-549.

Systematics of the Roanoke Bass, Ambloplites cavifrons

Ambloplites cavifrons is a poorly known centrarchid restricted to the Roanoke, Chowan, Tar and Neuse drainages of Virginia and North Carolina. It has been taxonomically confused with A. rupestris, the rock bass. Species rank for A. cavifrons is supported by comparisons with sympatric A. rupestris and other material in morphometric and meristic data, coloration and multivariate analyses. Hybridization between the two species is known at some of the sites of syntopy in the upper Roanoke, VA. The distribution of A. cavifrons has receded during historical times, apparently in part from interaction with introduced A. rupestris; A. cavifrons is threatened with further decline in the upper Roanoke River.

Long-term Trends in the Bogue Chitto River Fish Assemblage: A 27 Year Perspective

Abstract We conducted a thorough survey of the Bogue Chitto River fish assemblage from February 1996 to January 1997 to examine long-term trends in the assemblage by comparing our findings to surveys conducted in 1971–1974 and 1987–1988. The 1971–1974 survey described an assemblage dominated by Cyprinidae (50%), Percidae (9%), and Ictaluridae (8%). Numerically abundant species included Notropis longirostris (19%), Cyprinella venusta (13%), and Percina sciera (10%). The 1987–1988 survey described an assemblage dominated by Cyprinidae (74%), Percidae (9%), and Centrarchidae (9%). The numerically dominant species were C. venusta (36%) and N. longirostris (16%). Our survey described an assemblage dominated by Cyprinidae (75%), Percidae (8%), Centrarchidae (6%), and Poeciliidae (6%). We identified a decline in the relative abundance or possible extirpation of over twenty species during the 27-year period and the numerically dominant species was C. venusta (57%). Using Morisitas Index of Similarity, we found relatively low faunal similarity between the 1970–1974 survey and our study, but relatively high similarity between the 1987–1988 survey and our survey. In addition, assemblage evenness and heterogeneity decreased over time, indicating a change in the systems fish fauna from one with relatively high species evenness and diversity to a fauna dominated by a few, abundant species. We speculate that increased siltation has contributed to changes in the Bogue Chitto River fish assemblage because many of the declining species were benthic minnows and darters, which would be adversely effected by increasing substrate loads.

Evolutionary and Biogeographic Relationships of Fundulus catenatus (Fundulidae)

Evolutionary relationships among 21 geographic samples of the northern studfish, Fundulus catenatus, were inferred from genotype distributions at 24 presumptive gene loci. Phylogenetic treatment of allozymic data support a widespread ancestral distribution for the species in the region of the Central Highlands. Allozymic data further support a primary divergence between a Cumberland, Green, and Tennessee River segment of this ancestral distribution and an Indiana, lower Mississippi River, Ouachita, and Ozark population. Disjunct populations extant in the Ouachita Uplands represent an early divergence from an Indiana-Ozark-lower Mississippi River lineage. The White River, Indiana, and Ozark populations remain close relatives, with the lower Mississippi River populations diverging from this lineage. The inferred pattern of relationships is generally consistent with predictions based on recent hypotheses concerning the historical biogeography of the Central Highlands. One noteworthy point of divergence concerns the apparent close relationship between Ozark and Indiana populations. Such a pattern of relationship supports the persistence of gene flow across the region that is now the Central Lowlands after isolation of the Ouachita Highlands.