The butter catfish, Ompok bimaculatus, belonging to the silurid family, is widely regarded as an important food fish for aquaculture diversification in India. Furthermore, the species poses a threat due to habitat degradation and other anthropogenic factors, and has been categorised as “near threatened”, therefore, its culture promotion is warranted. To establish a successful breeding programme, a precise understanding of the life history, and biology (reproductive/feeding) of the fish will assist hatchery managers and researchers. Studies in these areas have been undertaken by several groups over the years, but without much coherence, the data are still fragmented. Few attempts on the culture attributes of this catfish have been performed under both mono- and polyculture systems to bring about parallel promotion through aquaculture in a larger part of the subcontinent. Highlighting this, we have tried to analyse and present a consolidated account of the morphological characteristics, feeding habits, reproductive biology, early developmental ontogeny, and culture potentials of O. bimaculatus in India. This review was also prompted by the paucity of information on the cultural aspects of the species. Additionally, based on the reported studies, future directions and perspectives of the culture promotion of the species are proffered to ensure future research initiatives.

Polybrominated diphenyl ether has become a widespread environmental pollutant in aquatic environments. BDE-209, a prominent PBDEs found in the environment and wildlife, has been proven to cause oxidative stress, immune damage and endocrine system disorders in fish. However, the effects of BDE-209 on the intestinal health of fish remain unclear. This research aimed to determine the effects of BDE-209 on the growth performance, digestive enzymes activities and intestinal microbiota of common carp. After 60-day exposure, the growth performance of common carp were remarkably decreased (P  0.05). Overall, exposure to BDE-209 could alter the intestinal microbiota of common carp, which may affect their growth and threaten their health.

Previous studies have speculated that tidal rhythm of Onchidium reevesii was linked to its memory ability, which has not been well explained. Mapk1 and egr1 genes are closely related to memory formation in the MAPK signaling pathway that have been extensively studied in vertebrates. These two genes are involved in Long-term potentiation (LTP), which is generally regarded as one of the main molecular mechanisms underlying learning and memory. To investigate the relationship between tidal rhythm of O. reevesii and its memory ability, we studied the molecular mechanism of mapk1 and egr1 genes cooperating with tidal rhythm. The full-length cDNA sequence of mapk1 gene was cloned by RACE method and analyzed by bioinformatics, then qRT-PCR was used to analyze its expression levels in each tissue. A homology analysis and phylogenetic tree reconstruction revealed that O. reevesii is most closely related to the Biomphalaria glabrata. The qRT-PCR showed that mapk1 was expressed in all the tissues, but the highest expression was in the ganglion. We speculated that mapk1 is related to memory formation of O. reevesii. Then we used qRT-PCR to detect the expression of mapk1 and egr1 in ganglion of O. reevesi under tidal stimulation. The expression of mapk1 and egr1 at the rising tide points were significantly higher (P 

Light is an essential natural factor of fish growth and development. A light regime in indoor aquaculture is critical for sustainable fish production. This research aimed to investigate the effect of light intensity and photoperiod on the growth performance and stress response of Nile tilapia (Oreochromis niloticus), which is an important commercial species, in a recirculating aquaculture system (RAS). Fingerlings with an average weight of 5 ± 0.9 g were randomly assigned to nine 1.5 m3 tanks with 145 fish in each tank, cultured under different light intensities (1000, 2000, and 3000 lx) and photoperiods (12L:12D, 18L:6D, 24L:0D), and fed to apparent satiation twice a day for 160 days. The growth of tilapia subjected to 2000 lx was significantly better than that exposed to 1000 and 3000 lx (P  0.05). Light intensity and photoperiod manipulation did not cause a significant chronic stress response in tilapia. This study demonstrated that light intensity, especially at 2000 lx, and photoperiod manipulation could stimulate the growth of tilapia in the RAS and significantly affect economic profitability. This study also served as an important reference for tilapia indoor aquaculture.