Congeneric species

Example of a Prey-Fish Indicator Yellow Perch Analyses of total mercnry in whole bodies or axial muscle tissue of age-1 yellow perch have provided a useful measure of MeHg concentrations in food webs of many North American lakes. This widely distributed species inhabits lakes and reservoirs across mnch of the north-central, northeastern, and eastern United States and across the central and eastern provinces of Canada (Scott and Crossman 1973 Becker 1983). An ecologically similar congeneric species, the Eurasian perch Perea fluvi-atilis), is distribnted across much of Europe and northern Asia (Thorpe 1977). 

The role of chemosignals in the maintenance of species isolation is supported by observations that the species L. jamesi, L. bellii, and L. lemniscatus, are able to discriminate between conspecifics and congeneric individuals (Labra et al. 2001 unpublished data). Moreover, these species do not discriminate between sympatric and allopatric congeneric species. In sympatry, the recognition of an individual as a non-conspecific reduces the possibility of hybridization among congeneric species. 

Luton, K., Walker, D. and Blair, D. (1992) Comparisons of ribosomal internal transcribed spacers from 2 congeneric species of flukes (Platyhelminthes, Trematoda, Digenea). Molecular and Biochemical Parasitology 56, 323-327. 

The logical and empirical facets of the analysis of threshold effects will be developed more fully when comparisons are made between con-familial and congeneric species that are found in habitats that differ only slightly in temperature. These comparisons of differently adapted, yet... 

Stillman, J.H., and G.N. Somero (1996). Adaptation to temperature stress and aerial exposure in congeneric species of intertidal porcelain crabs (genus Petrolisthes) correlation of physiology, biochemistry and morphology with vertical distribution. J. Exp. Biol., 199 1845-1855. 

Recently we have found a novel female-attracting peptide pheromone, sodefrin, in the abdominal glands of Cynops pyrrhogaster males (Kikuyama, Toyoda, Ohmiya, Mat-suda, Tanaka Hayashi, 1995). In this article, we review the isolation, characterization, and localization of this pheromone, as well as the hormonal control of its secretion and the possible existence of a precursor pheromone. A variant type of pheromone in a congeneric species (C ensicaudd) will also be a topic in this article. 

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