Abstract:
The freshwater cyprinid fish that has long been identified as Systomus sarana
(Puntius sarana) is a widespread species in Sri Lanka. Taxonomic complexity
of this species has been indicated by previous literature, but no scientifically
confirmed information is available on phenotypic variation of the species, and
whether the Sri Lankan species is in fact similar or different from Indian S.
sarana (s.l.). The present study aimed to describe the morphometric and
meristic characters of S. sarana (s.l.) in Sri Lanka, and to carry out a
comparative analysis with S. sarana from Kerala. High degree of variation in
morphology was evident among some of the studied populations (Menik River-
M, Kirindi Oya-KO, Nilwala River-N, Kelani River-K, Walawe River-WP,
Malwathu Oya-MO, Gin River-G and Kerala/India-IK). Univariate ANOVA
showed that, except Pre Doral Length, Post Dorsal Length, Caudal Peduncle
Depth and Maximum Body Depth, all the other characters were significantly
different (P<0.05) among studied populations. Discriminant function analysis
identified post orbital length as having the greatest power to discriminate the
populations. Significant separation of two groups of populations was possible
by canonical analysis, where CV1 and CV2 explained 69.7% of the total
variation in data. In cluster analysis, MO, K and IK populations create a
separate clade which probably shows a lineage splitting from the other clade
(M, KO, N, WP, and G) by having a linkage distance of -85%. Results from
meristic counts were also in agreement to this separation where number of
scale rows above lateral line was different between the two clades (4 Vi vs. 5
Vi). The results conclude that at least two clearly differentiable groups of this
fish are present in Sri Lanka, and one of which (MO and K) shares the
characters of Indian S. sarana more closely than the other group (M, KO, N,
WP, and G).
