Mitochondrial DNA variation in economically important fish species

Abstract

Mitochondrial DNA (mtDNA) markers (COI, cytochrome b, D-loop, ATPase 6/8) have become essential tools for assessing genetic variation, population structure, and phylogeography of economically important freshwater fishes. This review synthesizes mtDNA-based studies on Indian freshwater fishes, highlights results relevant to rivers that flow through Uttar Pradesh (particularly the Ganga basin), and evaluates marker performance for stock identification and conservation. Available studies indicate moderate-to-high mtDNA diversity in many carp and catfish taxa, frequent shallow spatial structuring for widespread species, and evidence that habitat fragmentation and anthropogenic pressures can reduce genetic connectivity. For Uttar Pradesh, published molecular sampling is relatively sparse; targeted mtDNA surveys across major Ganga tributaries are urgently needed to inform stock management and hatchery supplementation programs. Key recommendations include coordinated mtDNA barcoding and control-region surveys across UP rivers and integration with nuclear markers for robust management decisions.