Some 16 new species have been added to the list of fish in the country as a group of researchers of Chittagong University has identified these species in and around St. Martin's Island in the south-east coast.
The research was conducted in three phases from 2018 to 2020. The results of the study were published on the websites of three separate international publications.
Researchers have discovered these species by conducting scientific research in the tide pool (small water reservoir created from tides) of the rocky beach on the east and west coasts of St. Martin's Island, the shallow water of the west coast and the coastal areas of Teknaf.
Of these, 11 species have been discovered in the tide pool of St. Martin’s Island, one in Teknaf’s Jaliapara and six in the shallow waters in the west side of St. Martin’s Island. Tide pool is a naturally occurring downpour which can be found intertidal zone. Tide pools hold water permanently during low tide and create small reservoirs.
Researchers say tide pools are habitats of different kinds of marine fishes, invertebrates and a number of other species. Some fishes spend their entire life in tide pools. Again some species spend a specific phase of their life cycle in these tide pools while some others come to the tide pools in search of food for a short period.
According to the research, a total of 441 samples of some 20 species were collected. Following the procedure of classification and nomenclature, as many as 17 new species were identified. Another species was identified through DNA barcoding. The length of adult fishes of some 11 species is 19.20 to 40 millimetres. The length of adult fishes of the remaining six species is 37 to 220 millimetres.
Prof SM Sharifuzzaman of Institute of Marine Sciences was the supervisor of these research projects. Prof Saidur Rahman Chowdhury, Md Shahdat Hossain and M Shah Newaj Chowdhury were also in the research team. Apart from them, professor Ahsan Habib of Sher-e-Bangla Agricultural University and Seishi Kimura from Mie University of Japan were also involved in the research. Chittagong University financed the research projects.
The publication
The flying (urukku) fish is a well-known species of fish in St. Martin’s Island. At present, three species of flying fish are available in the coastal areas of the country. Researchers have identified a new species - Cheilopogon spilonotopterus.
The research regarding this was published in the journal ‘Conservation Genetic Resources’, an international publication, in February. This species of fish is found in the coastal area of the west coast of St. Martin’s Island. Six more species of fish are found in this area of St. Martin's Island and in Teknaf. Fishermen commonly know these species as ‘Katachanda’.
A research paper on these six species of fish was published in the ‘Journal of Fish Biology’, one of the fish classification journals of the international publication Wiley.
On the other hand, the research article on the 11 new species of fish obtained from tide pools was published in March this year. It was published in the journal Elsevier’s Regional Studies in Marine Science.’
The results of the research
The researchers say that due to a large number of tourists traveling to St. Martin’s Island and the pollution of the environment, the habitat of the fish in the tide pool is being damaged. The research projects provided accurate information about the community structure of the fishes in tide pools, the rate of population growth, and the biodiversity of the local fish.
SM Sharifuzzaman, the lead researcher on the research project, told Prothom Alo that the east coast of St. Martin’s Island has more fish and species as compared to the west coast. The reason for the decrease is that the pressure of tourists on the west coast is always high. In addition, the freshwater of the Naf River has a mild effect.
He further said that the main purpose of this study was to gain detailed knowledge about the nature of marine life. These fishes have been endangered due to natural and man-made causes. "So to preserve biodiversity, we have to preserve these newly discovered species of fishes."
According to the Bangladesh Fisheries Research Institute, the total number of fish species found in the marine waters of the country is 442. According to another publication in 1970, the number of fish species was 475. However, so far no detailed research has been done to determine the exact number of fish species, the researchers said.
18 new species
The researchers have named six of the new species by consulting with the fishermen and local residents. The work to name the remaining new species is still underway. However, all of the new species have scientific names.
The named six species are – ‘dorakata bang’ (Allenbatrachus reticulatus), ‘pathure bele’ (Bathygobius coalitus), ‘nunya bata’ (Crenimugil crenilabis), ‘Khorgosh’ (Signus sutor), ‘thutni kanta chanda’ (Deveximentum megalolepis) and ‘urukku machh’ (Cheilopogon spilonotopterus).
The scientific names of remaining unnamed 12 species are - Bathygobius curacao, Callogobius hasseltii, Halichoeres nigrescens, Istigobius decoratus, Istigobius ornatus, Ostorhinchus cookii, Yongenichthys nebulosus, Aurigequula longispina, Equulites leuciscus, Eubleekeria rapsoni, Gazza rhombea and Karalla daura.
*This report appeared in the print and online editions of Prothom Alo and has been rewritten in English by Ashish Basu