IMPACT OF LOCKDOWN RESTRICTION OF COVID-19 ON SELECTIVE DISSOLVED HEAVY METALS IN COASTAL WEST BENGAL

In this study, the effect of COVID-19 lockdown (2020) on dissolved heavy metal load (Zn, Cu, and Pb) in the coastal West Bengal were analyzed concerning the pre-COVID 19 phases (2016-2019). Two stations namely Shankarpur (Stn.1) and Haldia (Stn. 2) were selected for the study as both have two contrasting operational features. Haldia is an important port-cum-industrial complex whereas Shankarpur is an important fish landing station-cum-tourism site. The results showed that in both the stations there was a drastic fall in the metal concentrations due to lockdown implementation, but in Haldia, the aquatic health exhibits much improvement as in lockdown there was complete shut-down of the industries. ANOVA results also highlight significant variations between the two stations as well as between the pre COVID-19 (2016-2019) and COVID-19 lockdown phases.

A highly contiguous nuclear genome assembly of the mandarinfish Synchiropus splendidus (Syngnathiformes: Callionymidae)

The fish order Syngnathiformes has been referred to as a collection of misfit fishes, comprising commercially important fish such as red mullets as well as the highly diverse seahorses, pipefishes, and seadragons—the well-known family Syngnathidae, with their unique adaptations including male pregnancy. Another ornate member of this order is the species mandarinfish. No less than two types of chromatophores have been discovered in the spectacularly colored mandarinfish: the cyanophore (producing blue color) and the dichromatic cyano-erythrophore (producing blue and red). The phylogenetic position of mandarinfish in Syngnathiformes, and their promise of additional genetic discoveries beyond the chromatophores, made mandarinfish an appealing target for whole genome sequencing. We used linked sequences to create synthetic long reads, producing a highly contiguous genome assembly for the mandarinfish. The genome assembly comprises 483 Mbp (longest scaffold 29 Mbp), has an N50 of 12 Mbp, and an L50 of 14 scaffolds. The assembly completeness is also high, with 92.6% complete, 4.4% fragmented, and 2.9% missing out of 4,584 BUSCO genes found in ray-finned fishes. Outside the family Syngnathidae, the mandarinfish represents one of the most contiguous syngnathiform genome assemblies to date. The mandarinfish genomic resource will likely serve as a high-quality outgroup to syngnathid fish, and furthermore for research on the genomic underpinnings of the evolution of novel pigmentation.

Histo Hepatic Alterations in Commercially Important Fish (Pseudoplatystoma corruscans Spix & Agassiz, 1829) Exposed to a Glyphosate-Based Herbicide

The presence of herbicides in the aquatic environment can cause different effects at all levels of biological organization. This study aimed to evaluate the hepatic alterations of the herbicide Roundup WG® on juvenile Pseudoplatystoma corruscans exposed to three different concentrations of this chemical compound: 0.25g/1000L, 0.50g/1000L, and 0.75g/1000L, plus control treatment (0.00g/1000L). The experiment lasted sixty days and, in the end, liver fragments were collected for further histological processing, using the hematoxylin-eosin (HE) technique. Only the control group showed a statistically significant increase in body mass and total length during the experiment. Blood glucose also showed no difference among the sample groups. The lesions found in the liver considered severe were hemorrhage, vacuolization, and hypertrophy of hepatocytes and the presence of free melanomacrophages, recorded in the groups exposed to 0.50 and 0.75g/1000L. The results obtained in the present study indicate that the herbicide Roundup WG® can promote liver alterations in Pseudoplatystoma corruscans.