Plectorhinchus macrospilus Satapoomin et Randall, 2000

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

Plectorhinchus macrospilus Satapoomin et Randall, 2000

Local common name: dagi datina (Bangla) Fig. 2b

Material examined.

Bangladesh • 1 specimen; F1803SM-67 (335 mm SL), Cox's Bazar , Bay of Bengal, Saint Martin’s Island, 20°36'39.6"N, 92°19'37.2"E, 27 March 2018, Md. Jayedul Islam and Kazi Ahsan Habib, GenBank: MK340677 .

Diagnostic characters.

Meristics: D-XII, 21; P1-17; P2-I, 5; A-III, 8; C-18; LL-59; GR- 5 + 15.

Body compressed; dorsal profile of head strongly convex. Small mouth with fleshy lips, moderately thick; chin with 6 pores and no median pit. Dorsal fin slightly notched. Caudal fin truncate. Scales ctenoid; absent in front of snout, lips, and chin. Color of body whitish to grayish ground color on most parts of body; contrasting with many large, irregularly rounded black spots on body, nape, and soft portions of median fins, and smaller black spots on head. Posterior edge of opercle slightly serrate, margin of subopercle and interopercle smooth (Fig. 2b ). Lateral line continuous. Meristic measurements are given in Table 1 and Table 2 .

Remarks.

Plectorhinchus macrospilus is one of six species of its genus that have numerous dark spots in adults; others are Plectorhinchus chaetodonoides ; Plectorhinchus gaterinus ( Forsskål, 1775); Plectorhinchus picus (Cuvier, 1828); Plectorhinchus pictus (Thunberg, 1792); and Plectorhinchus cinctus (Temminck et Schlegel, 1843). The dark spots of P. macrospilus are generally larger than those of the other five species, and P. macrospilus also has greater number of dorsal soft rays (21 vs. 15-20 for other species). Subadult P. chaetodonoides are similar in coloration to P. macrospilus but are easily distinguished by gill raker count (9-12 + 28-33 versus 5 + 15 for P. macrospilus ).

Distribution.

Plectorhinchus macrospilus is known to occur from Thailand ( Satapoomin and Randall 2000) and Myanmar (Yangoon and Myiek Archipelago) ( Allen and Erdmann 2012; Russell 2016; Psomadakis et al. 2019). This study confirms its occurrence also in the northern Bay of Bengal.

Conservation status.

Not yet assessed, not listed in the IUCN Red List of Threatened Species (https://www.iucnredlist.org/species/123439745/123494892).

Figures

Figure 2. Lateral view of collected specimen, a. Plectorhinchus pictus, subspecies Plectorhinchus pictus cinerascens (F 1804 SM- 22; 105 SL mm), striped juvenile phase; b. Plectorhinchus macrospilus (F 1803 SM- 67; 335 mm SL); c. Plectorhinchus andamanensis, (F 1803 SM- 19; 137 mm SL); d. Pomadasys argenteus (F 1602 Sb- 01; 132 mm SL).