Ambloplites

Abstract: SUMMARY Two new parasitic crustaceans of African freshwater fishes are described. These are the copepod Ergasilus Zutue, from L. Rudolf, and the branchiuran. Chonopeltis flaccijrons from various parts of the Congo system. A description of the true male of Argulus ambloplites is given, and in the light of its structure it is suggested that A. jollymani is best regarded as a sub-species of A. ambloplites. The male of Argulus dartvellei is described for the first time. Notes of the specimens of Chonopeltis recorded from the Ue 16 and Okavango Rivers are given and it is shown that neither can be satisfactorily identified at present. Keys to the species of Chonopeltis are given. Some recently established diat ribution records of parasitic crustaceans of African freshwater fishes are listed.

Abstract: One thousand and forty-five rock bass (Ambloplites rupestis (Raf.)) were collected from May 1970 through October 1972 from the Bay of Quinte, Ontario. During the same sampling period, 1043 specimens of the same host were collected from West Lake, Prince Edward County, Ontario.Data were collected on three groups of gill parasites, Monogenea (four species), Copepoda (three species), and glochidia (one species). The data, treated synecologically, were analysed using a two-factor ANOVA and Duncan's multiple range test. The roles of season, habitat, host age, and sex on parasite load were analysed.Host sex was found to have no effect on the three groups of parasites. The abundance of parasites increased with host age (P < 0.001). A marked seasonal effect was noted for all three groups of parasites (P < 0.001). A eutrophic habitat, West Lake, was found significantly more favourable (P < 0.001) for Monogenea, while an oligotrophic habitat, Glenora, was clearly more favourable (P < 0.001) for Copepoda.

Abstract: 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.

Abstract: The average size for the various age groups is presented for seven Michigan fishes: the bluegill (Lepomis m. macrochirus), yellow perch (Perca flavescens), pumpkinseed (Lepomis gibbosus), rock bass (Ambloplites r. rupestris), largemouth black bass (Micropterus salmoides), smallmouth black bass (Micropterus d. dolomieu), and the black crappie (Pomoxis nigro-maculatus). Ages were determined for 25,723 specimens. Only two species showed consistent sex differences in growth rate. The female yellow perch grew more rapidly than did the males, and the male rock bass were consistently larger than the females of corresponding age. Sex ratio for each of the species also is presented. The percentage of males varied from 39 percent in the yellow perch to 52 percent for the pumpkinseed and black crappie. Weights for each of the age-groups were calculated from the length-weight equations.