The taxonomy of Indian gorgonians: an assessment of the descriptive records of gorgonians (Anthozoa: Octocorallia: Alcyonacea) recorded as occurring in the territorial waters of India, along with neighbouring regions and the Andaman and Nicobar Islands, and the highlighting of perceived unethical practice.

The descriptive taxonomic records of a total of 226 gorgonian species (Octocorallia: Alcyonacea) from Indian seas and neighbouring areas were surveyed and critically reviewed with the main aim of providing a more reliable checklist. The published accounts comprise: species originally described from within the region: subsequent descriptive records of the taxa originally described from within the region; and subsequent descriptive records of species originally described from outside of the region. The reviews include an attempt to assess the validity of all subsequent descriptive records, although in numerous cases the species have been assessed as unrecognisable from their type descriptions. Numerous new binomial combinations, some tentative, have been proposed. The assessment of the validity of a species record is expressed as an "Opinion" with supporting justification. Of the 226 species, there are 111 that were originally described from locations outside of Indian waters and have subsequently been described and recorded as occurring in the region. Of these, there are 9 species where we were unable to decide if the records are valid or not, 94 were assessed as invalid, 5 as possibly valid and 3 were considered valid. The survey highlights four major problems regarding the reliability of some more recently published taxonomic records for the region: the use of 'predatory journals'; plagiarism; the use of manipulated imagery in more than one description; and taxonomic decision apparently based on expediency.

DNA barcodes for the pipefish genus Corythoichthys (Actinopterygii: Syngnathiformes) from the Indian Ocean provide insights into cryptic diversity.

The syngnathiform genus Corythoichthys comprises a group of taxonomically complex, tail-brooding (Syngnathinae) pipefishes widely distributed in the Indo-Pacific region. Due to the presence of overlapping interspecific morphological characters, reliable taxonomic information on Corythoichthys is still lacking. Using 52 CO1 sequences, including seven newly generated, a phylogenetic analysis was carried out to understand the genetic diversity, distribution and 'species groups' within the genus Corythoichthys. Species delimitation using Automatic Barcode Gap Discovery (ABGD) analysis confirmed the presence of 13 species which include 'species-complexes' previously considered as a single taxon. Our results revealed the presence of three species groups, 'C. amplexus', 'C. conspicillatus' and 'C. haematopterus' and four unidentified/undescribed species in the wider Indo-Pacific realm. Interestingly, 60 sequences and a mitogenome identified as Corythoichthys in GenBank are misidentified at the genus level. Based on our findings, we suggest that the taxonomy and systematics of Corythoichthys need to be re-examined and validated using integrative methods, and care should be taken while selecting specimens for genetic studies.

Fish community structure and functional guild composition in a large tropical estuary (Vembanad Lake, India).

The fish guild structure of 96 fish species inhabiting the Vembanad Lake, an open, large, well-mixed coastal estuary along the south-west coast of India, was studied based on samples from upper (freshwater), middle (estuarine), and lower (saline) zones representing three major seasons (monsoon, post-monsoon, and pre-monsoon). Functional group assessment revealed seven ecological guilds (marine estuarine opportunists, freshwater, marine estuarine dependent, estuarine, catadromous, anadromous, and amphidromous), six feeding guilds (detritivore, zooplanktivore, herbivore, zoobenthivore, omnivore, and carnivore), three vertical distribution guilds (demersal, benthopelagic, and pelagic), five reproductive-mode functional groups (oviparous with pelagic eggs, oviparous with benthic eggs, oviparous guarders, viviparous and ovoviviparous), and five flow-preference guilds (rheophilic A1, eurytopic, rheophilic A2, rheophilic B, and rheophilic C). The estuary was characterized by high species diversity, low individual species abundance, complex guild structure, varying fish diversity from upper to lower estuary and higher proportion of marine rather than 'true' estuarine species. The absence of a significant relationship between season and fish guild structuring could be due to high resource availability in the estuary and low ecological connectivity between upper and lower estuarine zones as a result of anthropogenic interventions in the middle zone. Salinity variations considerably influenced the fish guild formation in the estuary. A drastic change in the hydrography of the estuary over the past sixty years due to topographical alterations has transformed the fish guilds resulting in a considerable increase in freshwater species and a reduction in marine and estuarine-dependant species.

Demographics of Lagocephalus inermis in the Arabian Sea unveils complex conservation challenges.

The first assessment of the demographics of Lagocephalus inermis, a species associated with pufferfish bites and fishing down the food web in the Arabian Sea, south-west coast of India, was performed based on length structured population dynamics of 1601 individuals caught in commercial fisheries. Analysis revealed that the current level of exploitation is 90% of the predicted exploitation producing maximum relative yield per recruit (Emax ), suggesting high levels of exploitation with potential for significant negative consequences for trophic cascades.

Population dynamics of a poorly known serranid, the duskytail grouper Epinephelus bleekeri in the Arabian Sea.

A demographic study on Epinephelus bleekeri based on a sample of 1,003 individuals caught in commercial fisheries along the Arabian Sea coast of southern India considerably extends the maximum recorded standard length for this species to 870 mm, indicates a high natural mortality rate and an exploitation level (E) greater than the Emax .