Reproduction and feeding habits of the River Catfish Eutropiichthys vacha (Hamilton, 1822) (Siluriformes, Schilbidae) in an impacted habitat: Kotri hydrodam, River Indus, Pakistan

Abstract

Reproduction and feeding habits of Eutropiichthys vacha were studied in Kotri hydrodam, a man-made and human impacted stretch of the Indus River, Pakistan during [2005][2006]. A total 303 specimens were sampled and analyzed for maturity stages and gonadal development and food and feeding habits assessed from gut contents. Results showed male dominance over females: sex ratio 1.16:1.0. Minimum size at sexual maturity was 13.9 cm total length (TL). Mean fecundity ranged 1.38x10 4 to 2.17 x 10 5 . Gonado-somatic index (GSI) was 0.1-2.5 and 0.3-6.5 for males and females, respectively. Highest GSIs were recorded in April. We observe an ontogenic dietary shift in E. vacha: young are omnivorous with insects dominating diet while adults are omni-piscivores with Puntius ticto accounting for 35.4% of species. Other species were Colisa spp., juveniles of Channa spp. and some cyprinids. Feeding intensities were lowest in April at peak of spawning. The intensities increase rapidly after spawning indicating voracious feeding in E. vacha. Feeding intensities in adults are low during the cold season. These results provide for assessment of spatial-temporal variations in feeding intensity in E. vacha while GaSI and diet composition reveal information on environmental shifts and ecosystem fluctuations in the impacted habitats of the River Indus for sound fisheries management.

Population Parameters of Siluroid Catfish (Eutropiichthys vacha) from Indus River, Pakistan

“…The calculated t0 value was close to our current study for E. vacha for combined sexes but high values were obtained in male and female from Indus River, Pakistan (Table 4). This may be due to onset of spawning during March-May when feeding intensities in adult E. vacha decreases towards the peak of spawning season, and after spawning in June-July the feeding intensities increased rapidly according to Soomro et al (2012). According to King (1997) the value of t0 is an indicator of growth rate in juveniles as well as adults.…”

Patterns of fish community composition and biodiversity in riverine fish sanctuaries in Bangladesh: Implications for hilsa shad conservation

“…We collected data on trophic category, trophic level and habitat groups from the Web-based relational database FishBase (Froese & Pauly, 2017) and IUCN (2015). Whenever data were unavailable on FishBase, data were collected from various local and internal published articles (Gupta & Banerjee, 2014;Hoque, Mandol, & Ahmed, 2016;Hossain, Sarmin, Alam, Alam, & Mokhtar, 2015;Karmakar & Biswas, 2015;Masud & Singh, 2018;Soomro, Baloch, Jafri, Burdi, & Fulanda, 2012). For functional group analyses, all the identified species were assigned to three broad functional groups based on feeding mode (herbivore, carnivore/predator or scavenger/ omnivore).…”

Reproductive Biology of Glossogobius giuris (Hamilton), in Manchar Lake Sindh, Pakistan

“…Based on the size of smallest female carrying the mature ovaries (9.4 cm), this can be concluded that the maturity size of the fish in Manchar lake is 9.4 cm. Previously size of sexual maturity was estimated based on smallest egg bearing female by Soomro et al [10].…”

“…Knowledge about Gonadosomatic Index and fecundity of any fish is important for understanding its life history, and evaluating the potential of its stock for commercial purposes. Furthermore, such knowledge is also needed for the sound management for the conservation of the Gupta and Shrivastava [9][10][11][12].…”