Life Sciences Commons^™

Heterogeneity within a population enhances its long-term survival. A fundamental method of maintaining population heterogeneity is the retention of rare or uncommon phenotypes by selective mating strategies. Employing two color morphs, red tuxedo and red, of the guppy (Poecilia reticulata, Poeciliidae), this study was designed to investigate whether P. reticulata females would preferentially seek out heterogeneous groupings of males exhibiting two color morphs. Adult female guppies were exposed simultaneously to two groups of males (n=10); one comprised of only the tuxedo color morph (n=5) and the other of both color morphs (n=5). For the latter group, the ratio of males …

The croaking gourami (Trichopsis vittatus) exhibits two phenotypes associated with humeral spotting. Fish possess a prominent, dark humeral patch or spot located behind the operculum or lack this spotting pattern. Segregation patterns observed from the progenies of eleven different crosses support the hypothesis that the inheritance of humeral spotting in T. vittatus is controlled by the action of a single autosomal locus, with complete dominance of the allele controlling the spotted phenotype.

The tetra (Hyphessobrycon bentosi) exhibits two phenotypes associated with shoulder spotting. Fish possess ei-ther a prominent black vertical spot located directly behind the operculum (H. b. bentosi,  bentosi  white  tip  tetra) or  lack  this spot (H. b. rosaceus, rosy tetra). Segregation patterns observed from the progenies of ten different crosses suggest that the  inheritance  of  these  phenotypes  is  controlled  by  two  autosomal  loci  acting  in  a complementary  fashion,  with  domi-nance at both loci required for the expression of the spotted phenotype. 

Labyrinth  fishes  of  the  families  Anabantidae,  Belontiidae,Helostomatidae,  and  Osphronemidae  comprise the  tradi-tional  anabantoids,  a  group  of  about  80  relatively  small African  and  southeast  Asian  species (Linke  1991).  Many of  the  anabantoids  are  popular  with  aquarium  hobbyists because of their interesting reproductive behaviours, with males of most species brooding eggs in their mouths or in floating bubble nests (Vevers 1980; Linke 1991; Axelrod and Vorderwinkler 1995; Mills 2000). They have also beenthe focus of several environmental, morphological, and gene-tic  investigations  (Sommer  1982;  Gosline  1985;  Waki-yama  et  al. 1997;  Frankel  1992,  2001).  The  two-spot gourami,   Trichogaster  trichopterus  trichopterus  Pallas (Osphronemidae),  is …