Morphological heterogeneity in some estuarine populations of the catfish <i>Arius jella</i> (Ariidae) in Sri Lanka

Abstract

Intra-specific morphological variation in the indigenous catfish Arius jella (Ariidae) was studied in five estuarine localities in Sri Lanka (Koggala lagoon, Walawe estuary, Garanduwa lagoon, Nilwala estuary and Chilaw lagoon) using morphometric analysis. Five morphometric characteristics describing the shape of the fish were significantly different among some of the locations. Significantly shorter pre-orbital length (8.3% SL vs 9.2-10.7% SL in the other populations) in specimens from Walawe estuary is a populationspecific character. Significant differences in other characteristics were found indicating heterogeneity in morphology. The first two canonical variates (CV) explained 82.7% of the total variation in the data, yet the plot of the CV failed to display significant separation of the sample populations. Derived classification functions could correctly classify an average of less than 50% individuals into their a priori groups. There was no agreement on the isolation by distance model. The results indicate a small degree of spatial separation in morphology in A. jella among the studied estuarine localities.

Genetic Fitness and Bottleneck of Threadfin (Sea Catfish), Arius arius (Hamilton, 1822) in South Indian Coastline

“…There were no differences observed in the meristic characters of the five populations. Consistent results were found as in the previous studies [16].…”

“…One way univariate ANOVA showed significant difference in some morphometric characters among the five populations (Table 2). But in the previous studies, the significant spatial heterogeneity was found in estuarine populations [16]. Generally, the morphological variation is expected to be under isolation by distance model.…”

“…Morphometric and meristic characters were measured based on the method of Gunawickrama [16]. All the morphometric data of the five populations were analyzed using univariate analysis of variance (ANOVA) and Tukey HSD (for unequal N) post hoc comparison tests to investigate the significant morphometric differences.…”

Morphological and mitochondrial DNA variation revealed an undescribed lineage under the genus Sperata (Bagridae) in Bangladesh

“…Letters: n = within Sperata sp. Intraspecific morphological variation showed discrepancy in morphometric characteristics among the indigenous catfish Arius jella (Ariidae), with significant difference between the locations (Gunawickrama, 2007). and Sperata seenghala; nva = between Sperata sp.…”

Genetic Differentiation Studies among Natural Populations of <i>Tilapia zillii</i>

“…Morphometric characters are generally being used in discriminating many fish species in several parts of the world (Gunawickrama, 2007;Murta, 2000), in Africa (Teugels, 1992;Hassanien et al, 2011) and also in Nigeria (Eyo 2002(Eyo , 2003Anyanwu and Ugwumba, 2003;Edema and Osagiede, 2011;Kuton and Adeniyi, 2014). However, morphological description alone has proved to be unreliable in establishing genetic relationships within and between species.…”