Genetic diversity and demographic history of the giant river catfish Sperata seenghala inferred from mitochondrial DNA markers

Abstract

The giant river catfish Sperata seenghala has huge demand in South Asian countries due to its low number of intramuscular bones and nutritive value. However, the culture practises for this fish have not been standardized and the current demand for this fish is being met by capture fisheries only. Unregulated and indiscriminate fishing would lead overexploitation of fish stocks subsequently stock depletion. Genetic diversity between populations would give insight about population structure and demography. In the present study, S. seenghala stocks from three rivers, namely Ganga, Brahmaputra and Mahanadi were characterized using cytochrome b gene and D-loop region. Moderate to high haplotype diversity and low nucleotide diversity values were observed in all populations. Analysis of molecular variance and pairwise F values showed significant genetic differentiation among populations. Patterns of diversity, haplotype networks and mismatch distribution strongly suggest a historical influence on the genetic structure of S. seenghala populations. S. seenghala stocks from these three rivers are genetically distinct units and management measures should be formulated separately for each population.

Molecular evidence indicates the existence of multiple lineages ofSperata speciesin Indian Rivers

“…The results indicated the low genetic divergence between Ganga–Brahmaputra than the Mahanadi populations, with comparatively low genetic diversity from the Ganga river due to the presence of excess homozygotes. In contrast to this, our mtDNA results showed Ganga seenghala is genetically close to Mahanadi than the Brahmaputra, which is supported by a previous study based on cytochrome b and D-loop region (Kumari et al . 2017).…”

“…Clade IA widely distributed throughout the Ganga, whereas Clade IB confined to lower stretch of Ganga, i.e, Munger district, Bihar. Interestingly, when we compared the data with Kumari et al . (2017), the two sequences (accession no.…”

“…PCR amplification was performed using mtDNA control region (CR) primers SSDLoop F:5◻-CACCCCTAACTCCCAAAGC-3◻, and SSDloop R:5◻-GGTTTAGGGGTTTAACAGG-3◻(Kumari et al , 2017). PCR reaction was performed in total reaction volumes of 20 μl using a 1 X PCR buffer (10 mM Tri –HCl, pH 8.3, and 50 mM KCl), 1.5 mM MgCl 2 , 0.2 mM of each dNTP, 2 pmol of each primer, 5 U of Taq DNA polymerase and 1 μl (~30 ng) of the template DNA.…”

“…S. seenghala and S. aor are recognized as “least concern” in the RedList of International Union for Conservation of Nature (IUCN). Previous studies on giant river catfish gradually focused on the genetic assessment of S. seenghala using Randomly amplified polymorphic DNA (RAPD) marker (Saini et al , 2010; Garg et al , 2014), mtDNA markers (Kumari et al , 2017), and microsatellite marker (Acharya et al , 2019). The microsatellite-based stock discrimination of S. aor revealed the existence of three genetic stocks from the connected vicinity of the Ganga river (Nazir & Khan, 2017).…”

Phylogeography of Baryancistrus xanthellus (Siluriformes: Loricariidae), a rheophilic catfish endemic to the Xingu River basin in eastern Amazonia

“…Reduced π values associated with high h values usually indicate bottleneck events followed by population expansion, thereby leading to accumulation of new mutations [50,51]. A similar pattern suggestive of population expansion was reported in another species of Loricariidae, Hypostomus ancistroides, [52], as well as in other families of Siluriformes [53][54][55].…”