Abstract
Previously recognized color and pattern variants of adult Cichla temensis in Amazon flood pulse river environments reflect the cycling of individuals through seasonal sexual maturity and spawning. Individuals also vary in shape from blocky to fusiform. To determine if shape differences are related to patterns of fat reserve deposition and utilization, and to quantify the relationship of shape with color and pattern variation and life history status, specimens in each of four previously defined grades of color and pattern variation were compared using geometric morphometric techniques. Progressive shape changes occurred between grades independent of sex and correlated to gonosomatic index (GSI). Thin plate spline deformation visualizations indicate that the observed shape differences are related to fat deposition patterns. The seasonal timing of shape change and its link to color pattern variation, sexual maturity and local water level conditions suggests a relationship between the physiological and behavioral characteristics of C. temensis and the cyclical flood pulse pattern of its habitat.
Highlights
Cichla is a genus that comprises 15 Neotropical species
We apply geometric morphometric techniques to quantify the shape variation observed in C. temensis and we examine the hypothesis that there is a relationship between this shape change with color and pattern variation (CPV) grade and cyclical seasonal environmental fluctuations
Much of the variation was due to fatty reserve deposition in specific areas known to be potential reserve storage sites (Arrington, 2006) and which were observed in this study to contain adipose cells, implying that increased energy storage in these tissues was responsible for the change
Summary
Cichla is a genus that comprises 15 Neotropical species. All are large, diurnal and primarily piscivorous predators. Cichla temensis is the largest species with a natural range that consists primarily of blackwater flood pulse rivers with extremely variable seasonal environments (Val & AlmeidaVal, 1995) in Brazil, Venezuela and Colombia. Different color and pattern variants of Cichla temensis coexist in their natural environments. The morphological variation within C. temensis was previously attributed to assumptions that the variants were different species, subspecies or an effect of sexual dimorphism (Braga, 1953; Myatt et al, 2005; Kullander & Ferreira, 2006). A recent study has shown that the variants are all members of the same species and the differences in color and pattern among the variants are due to individual fish cycling through a series of changes correlated to seasonal gonad maturity (Reiss et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
