Intraspecific Variation in Morphology and Sexual Dimorphism in <i>Puntius singhala</i> (Teleostei: Cyprinidae)

Abstract

Intraspecific morphological variation and differentiation among six populations of the endemic freshwater fish Puntius singhala (Cyprinidae) were investigated. There is significant sexual dimorphism in three morphometric characters (pectoral-fin length, caudal-peduncle length, and length of dorsal-fin base), where males have slightly longer measures than females, indicating adaptive significance related to dispersal. Significant heterogeneity and differentiation was found only among some of the populations studied (Wilk's λ for males = 0.079 and for females = 0.129) indicating limited geographic variation, as suggested by relatively large overlap in canonical scores among most of the samples. No significant correlation between the pair-wise differences and inter-locality geographic distances was found, thus isolation-bydistance was not a plausible explanation for the observed variation. The present results show that P. singhala is not phenotypically homogenous. The absence of differences between population samples that experience highly limited present-day interchange may be partly explained by colonization history.

Fish Assemblage Structure of Two Contrasting Stream Catchments of the Mahaweli River Basin in Sri Lanka: Hallmarks of Human Exploitation and Implications for Conservation

“…kamalika are endemic and have been recently identified elsewhere in Sri Lanka [12] and were probably previously misidentified as P. filamentosus and P. amphibius, respectively [34,72]. Some of the species known to occur in the southwestern ichthyological province (type locality) were identified in the Mahaweli ichthyological province, which include C. brachysoma, D. pathirana and P. kamalika [2,12].…”

Studies on morphological variation in three barbin fishes (Cyprinidae:Barbinae) from different water areas of Manipur, India

“…Morphological variations among various species of fish populations (Wimberger, 1991;1992) and the involvement of environmental factors (Carvalho, 1993) have been documented from various species. Geographical variation and other forms of intraspecific phenotypic differences in freshwater fishes among different river/ lake systems have been documented by Guenette et al (1992); Jerry and Cairns (1998); Hänfling and Brandl (1998) ; Dynes et al (1999); Gunawickrama (2008). Fishes are considered to be phenotypically more variable than most other vertebrates, having relatively higher within-population coefficients of variation of phenotypic characters (Carvalho, 1993).…”

Sexual Dimorphism in Commercially Important Fish Species in India: A Review

“…Many studies showed variation in the length of fins between males and females as reported in cyprinids such as Puntius and Pethia sp. (Gunawickrama 2009;Mieno and Karino, 2017;Sharma and Ali, 2022).…”