Culture Possibilities of Certain Brackishwater Species at Freshwater: A Climate Change Adaptation Strategy for Salinity Intrusion Prone Areas of Indian Sundarban Delta

Salinity intrusion into coastal mainland or freshwater habitat because of recent climatic changes is exacerbating production risks and challenging the coping capacity of freshwater fish farmers of Sundarban coastal delta in India. Hence, an experiment was conducted to evaluate the survival and growth performance of certain commercially important brackish water species in freshwater, and subsequent low salinities (5 g l−1 and 10 g l−1). Species like Scatophagus argus, Chelon parsia, Terapon jarbua, Etroplus suratensis, and Penaeus monodon showed the highest specific growth rate (SGR) at 10 g l-1 salinity. However, the growth rates were not differed significantly (P>0.05) compared to freshwater. Chelon planiceps and Mystus gulio exhibited the highest SGR at 5 g l-1 salinity, although growth rates of the fish were not differed significantly (P>0.05) with freshwater treatments. Comparable survival and growth of all species in the freshwater condition indicated their ability of healthy acclimation at freshwater ponds. Therefore, these euryhaline fish species can be promoted in the Indian Sundarban for culture in freshwater ponds as climate-resilient adaptation strategies. This study could be useful in decision making during species and farm site selection which eventually will minimize the risks from total crop loss during saltwater inundation.

Length–weight relations of 14 fish species (Actinopterygii) from the Chalakudy River, Western Ghats, India

Length–weight relations of 14 fish species caught by small-scale fishery from the Chalakudy River of the Western Ghats biodiversity hotspot, India were analyzed from April 2018 to March 2019. The following species were studied: Amblypharyngodon microlepis (Bleeker, 1853); Dawkinsia filamentosa (Valenciennes, 1844); Puntius mahecola (Valenciennes, 1844); Osteobrama bakeri (Day, 1873); Labeo dussumieri (Valenciennes, 1842); Channa marulius (Hamilton, 1822); Channa striata (Bloch, 1793); Horabagrus brachysoma (Günther, 1864); Mystus armatus (Day, 1865); Pangasianodon hypophthalmus (Sauvage, 1878); Heteropneustes fossilis (Bloch, 1794); Etroplus suratensis (Bloch, 1790); Megalops cyprinoides (Broussonet, 1782); Parambassis thomassi (Day, 1870). The main fishing gear that was used in the data collection were gill nets, seine nets, and cast nets. The b values in the LWRs ranged from 2.649 (L. dussumieri) to 3.023 (P. hypophthalmus). This study reports the first LWR reference for five species and new maximum total lengths for five species. The results provide baseline information for the sustainable management and conservation of the studied species.

Length–weight relations of 14 fish species (Actinopterygii) from the Chalakudy River, Western Ghats, India

Length–weight relations of 14 fish species caught by small-scale fishery from the Chalakudy River of the Western Ghats biodiversity hotspot, India were analyzed from April 2018 to March 2019. The following species were studied: Amblypharyngodon microlepis (Bleeker, 1853); Dawkinsia filamentosa (Valenciennes, 1844); Puntius mahecola (Valenciennes, 1844); Osteobrama bakeri (Day, 1873); Labeo dussumieri (Valenciennes, 1842); Channa marulius (Hamilton, 1822); Channa striata (Bloch, 1793); Horabagrus brachysoma (Günther, 1864); Mystus armatus (Day, 1865); Pangasianodon hypophthalmus (Sauvage, 1878); Heteropneustes fossilis (Bloch, 1794); Etroplus suratensis (Bloch, 1790); Megalops cyprinoides (Broussonet, 1782); Parambassis thomassi (Day, 1870). The main fishing gear that was used in the data collection were gill nets, seine nets, and cast nets. The b values in the LWRs ranged from 2.649 (L. dussumieri) to 3.023 (P. hypophthalmus). This study reports the first LWR reference for five species and new maximum total lengths for five species. The results provide baseline information for the sustainable management and conservation of the studied species.