Pomadasys maculatus (Bloch, 1793)

Habib, Kazi Ahsan, Islam, Md Jayedul, Nahar, Najmun, Rashed, Mohammad, Neogi, Amit Kumer & Russell, Barry, 2021, Grunts (Actinopterygii: Perciformes: Haemulidae) of Bangladesh with two new distributional records from the northern Bay of Bengal assessed by morphometric characters and DNA barcoding, Acta Ichthyologica et Piscatoria 51 (3), pp. 299-309 : 299

Pomadasys maculatus (Bloch, 1793)

Local common name: guti datina (Bangla) Fig. 3c

Material examined.

Bangladesh • 4 specimens; F1602sb-38-2 (91 mm SL), Alorkol , Sundarbans, Bagerhat, 21°42.35'N, 89°35.24'E, 10 February 2016, Amit Kumer Neogi, GenBank: MF588665 ; F1708SM-10 (96 mm SL), Cox's Bazar , Bay of Bengal, Saint Martin’s Island, 20°36'39.6"N, 92°19'37.2"E, 29 August 2017, Amit Kumer Neogi, GenBank: MK340692 ; F1708SM-11 (98 mm SL), Cox's Bazar , Bay of Bengal, Saint Martin’s Island, 20°36'39.6"N, 92°19'37.2"E, 20 August 2017, Kazi Ahsan Habib, GenBank: MK340693 ; FCC1901SB-14 (101 mm SL), Cox's Bazar , Bay of Bengal, Saint Martin’s Island, 20°36'39.6"N, 92°19'37.2"E, 20 January 2019, Md. Jayedul Islam, GenBank: MN458364 .

Diagnostic characters.

Meristics: D-XII, 14; P1-17; P2-I, 5; A-III, 7; C-18

Body compressed; head blunt and dorsal profile convex; mouth small and slightly oblique; maxilla reaching to eye; narrow bands of small pointed teeth in the jaws. Scales ctenoid, moderate; present on head excluding snout. Chin with two pores and a median pit. Lateral line slightly arched. Body color silvery white, nape and back with a series of incomplete variable cross bars on the upper half of the body; spinous dorsal fin large with black blotch; dorsal and caudal fins edged with black, other fins yellowish (Fig. 3c ).

Distribution.

Pomadasys maculatus is reported in Bangladesh; elsewhere from east coast of Africa, Madagascar, Red Sea, Gulf of Aden, Persian Gulf, Pakistan, India, Sri Lanka to northern half of Australia from Shark Bay to Moreton Bay, New Guinea, Philippines to southern Japan ( McKay 2001; Habib et al. 2020).

Conservation status.

Listed as 'Least Concern’ in the IUCN Red List of Threatened Species ( Collen et al. 2010).

Genetic description.

We successfully barcoded six of the seven collected grunt species viz. Plectorhinchus macrospilus , Plectorhinchus pictus , Pomadasys andamanensis , Pomadasys argyreus , Pomadasys guoraca , and Pomadasys maculatus , and submitted to GenBank (NCBI) and BOLD system. The COI sequences of Plectorhinchus macrospilus , Pomadasys andamanensis , and Pomadasys guoraca were submitted for the first time to GenBank as reference DNA barcode sequence. We identified 11 COI barcode sequences of 6 species. For Pomadasys argenteus , we were unable to obtain a clear sequence. Sequence alignment of COI gene yielded about 602 nucleotide base pairs after removing the ambiguous sequences near primer ends. The COI sequences of 11 individuals of 6 species comprised 11 haplotypes with 174 polymorphic sites. The estimated mean ratio of transition and transversion was 2.88. The sequence analysis revealed that the mean nucleotide compositions in 11 COI sequences of 6 species were A = 22.5% ± 0.52%, T = 28.11% ± 0.59%, C = 30.45% ± 0.63%, G = 18.95% ± 0.71%. The overall GC content was 49.39%. The nucleotide diversity was calculated as 0.134 and the haplotype diversity was 1.0 for the sequences. The mean interspecific distance was 23.4% among the six species studied. The overall genetic distance among the sequences of COI gene was 16.3%. Among the six grunt species of the presently reported study, the highest pairwise genetic distance was found as 23.36% between Plectorhinchus pictus and Pomadasys argyreus , and the lowest distance (9.9%) was found between Plectorhinchus macrospilus and Plectorhinchus pictus .

In the phylogeny, we used 11 COI sequences of six species obtained in the presently reported study and three other sequences of Pomadasys maculatus , Pomadasys argyreus , and Plectorhinchus pictus retrieved from GenBank. The phylogenetic tree showed six clades, each belonging to the separate species (Fig. 4 ). No valid conspecific sequence of Plectorhinchus macrospilus , Pomadasys andamanensis , and Pomadasys guoraca was found in GenBank for comparison. However, the COI sequence of these three species clearly formed three separate clades from other species of grunt in the constructed ML tree with over 90% bootstrap value.

Figures

Figure 3. Lateral view of a collected specimen, a. Pomadasys argyreus (F 1712 SM- 14.; 129 mm SL); b. Pomadasys guoraca (F 1709 SM- 09; 197 mm SL); c. Pomadasys maculatus (F 1708 SM- 10; 96 mm SL).

Figure 4. Maximum-likelihood tree constructed for COI barcode sequences of grunt species obtained in the presently reported study (Bangladesh) and for conspecifics reported in GenBank. The GenBank accession numbers and country of origin are given within parenthesis beside species name. Numbers on nodes represent support values for Maximum-Likelihood (bootstrap). Bootstrap support of> 70 % are shown above branches. Scale bar indicates number of nucleotide substitutions per site. Sequences of Lethrinus nebulosus and Gymnocranius griseus were used as outgroups.