Assessing the sustainability of lepidophagous catfish, Pachypterus khavalchor (Kulkarni, 1952), from a tropical river Panchaganga, Maharashtra, India

Abstract

Background: The Western Ghats of India, one of the global biodiversity hotspots and freshwater eco-regions, harbors several fish species which not just form the important part of the world's freshwater biodiversity yet in addition are the vital segment of livelihood of the neighborhood population. The rate of fish decline in the Western Ghats is alarming. The absence of organized study and data scarcity on basic biology and life history traits of several species could be one reason behind the decline, and thus it is difficult to execute conservation action/s. This is especially true, particularly for data-deficient species for which definite data related to distribution, population size, and trend is not available. The present study deals with the detailed investigation of population dynamics of catfish species, Pachypterus khavalchor, which is data-deficient species inhabiting the Western Ghats of India and forms an important component of freshwater inland fishery, providing nutritional and financial security to the local community. Methods: Specimens for the present study were collected monthly for a period of 1 year from the River Panchaganga and length-frequency data were analyzed using FiSAT II software. Results: Length-weight analysis of pooled (male + female) data suggested the fish exhibited higher exponent than expected under isometry, indicating the positive allometric growth of P. khavalchor in the Panchaganga River. The asymptotic length (L∞) and the growth rate (K) were estimated as 149.63 mm and 0.71 year −1 respectively. Potential longevity (t max ) and length at first capture (Lc) were estimated as 4.22 years and 73 mm respectively. The total (Z), natural (M), and fishing mortality (F) were estimated as 2.23 year −1 , 0.88 year −1 , and 1.35 year −1 respectively. The current exploitation rate (E cur = 0.60) was found to be almost 90% that gives the maximum relative yield per recruit (E max = 0.67). Recruitment pattern revealed two peaks, suggesting the fish have two spawning bouts each year. Conclusions: The stock of P. khavalchor in the Panchaganga River may be in near full exploitation under the current harvesting strategy, with a high chance of recruitment failure in the future. Additional studies on the reproductive biology of P. khavalchor would be particularly welcome for the imposition of the seasonal closure for effective conservation of stock.

Population structure of Indian river shad, Gudusia chapra (Hamilton, 1822) from the Rupsha River, south-west Bangladesh

“…Nevertheless, the growth pattern of a particular species may vary due to geographic differences (Jisr et al 2018). In addition, variation possibly resultant because of seasonality, sex, availability of feed and physiological condition (Gosavi et al 2019;Le Cren 1951). Moreover, the LLRs were found highly correlated for both sexes of G. chapra.…”

First report on population dynamics and stock status of Badis badis in a wetland ecosystem (NW Bangladesh): Insights from new recorded maximum length

“…A recent study was conducted on important biological parameters of B. badis [ 26 ]. As fisheries management relies on other factors, having specific data about population parameters like growth, death rates, and recruitment is crucial for the implementation of proper management policies [ [46] , [47] , [48] ]. The LFD serves as a crucial biometric indicator for evaluating the changing patterns of recruitment, growth, mortality, yields, and the overall stock biomass within a specific ecosystem [ 49 , 50 ] by using dynamic mathematical models [ 49 , 51 ].…”

Assessing the Population Dynamics of Cirrhinus reba (Hamilton, 1822) in River Atrai, India, for its Conservation and Sustainability as Natural Stock

“…The growth performance index in C. reba was lower than that observed in closely related cyprinid fish such as Cirrhinus mrigala (6.180), as studied by Ramulu et al (2022) in the Thamirabarani River, South India. Fast growth rates and growth performance indices may enhance a species' potential for aquaculture (Gosavi et al, 2019). The occurrence of immature fish in the catch indicated a more or less continuous spawning period throughout the year, with a single recruitment pulse between June and August.…”