Plectorhinchus makranensis, Damadi & Moghaddam & Ghassemzadeh & Ghanbarifardi, 2020

Damadi, Ehsan, Moghaddam, Faezeh Yazdani, Ghassemzadeh, Fereshteh & Ghanbarifardi, Mehdi, 2020, Plectorhinchus makranensis (Teleostei, Haemulidae), a new species of sweetlips from the Persian Gulf and the Gulf of Oman, ZooKeys 980, pp. 141-154 : 141

Plectorhinchus makranensis sp. nov. Figs 1 , 2 , 3 , 4 , 5 , 6 ; Suppl. material 1: Table S1, Suppl. material 2: Table S2

Holotype.

(Fig. 3 ). ZMFUM-HA-56, 246.5 mm SL Type locality. Iran Gulf of Oman, Sistan and Baluchestan prov, Beris coast, 24°36'14"N, 61°45'77"E, depth 15 m, collected by Ehsan Damadi, 5 Aug 2017.

Paratypes (N = 15). ZMFUM-HA-31, 141.2 mm SL, ZMFUM-HA-75, 226.6 mm SL, ZMFUM-HA-205, 345.6 mm SL, ZMFUM-HA-147, 295.3 mm SL and ZMFUM-HA-148 203.1 mm SL, all from the Gulf of Oman, Sistan and Baluchestan prov, Tis coast, 25°7'60"N, 61°6'28"E, depth 5 to 7 m, collected by E. Damadi, 10 Sep 2017; ZMFUM-HA-4, 246.5 mm SL and ZMFUM-HA-2, 228.5 mm SL, Gulf of Oman, Hormozgan prov, Pozm coast, 25°17'48"N, 59°59'12"E, depth 6 m, collected by M. Kahouri, 12 Oct 2017; ZMFUM-HA-44, 268.3 mm SL and ZMFUM-HA-45, 274.5 mm SL, Gulf of Oman, Hormozgan prov, Jask coast, 25°36'63"N, 57°45'37"E, depth 6 m, collected by H. Rahmani, 5 Nov 2017; ZMFUM-HA-74, 248.6 mm SL, and ZMFUM-HA-76, 301.1 mm SL, Gulf of Oman, Hormozgan prov, Jask coast, 25°28'43"N, 57°49'36"E, depth 6 to 9 m, collected by A. Amiri, 7 Dec 2017; ZMFUM-HA-78, 277.5 mm SL, ZMFUM-HA-87, 263.3 mm SL and ZMFUM-HA-116, 287.3 mm SL, Persian Gulf, Bushehr prov, Kangan Bandar, 27°33'20"N, 52° 7'09"E, depth 10 m, collected by H. Tangestani, 13 Apr 2018; ZMFUM-HA-89, 146.5 mm SL, Persian Gulf, Khuzestan prov, Henijan coast, 29°37'35"N, 49°59'79"E, depth 7 m, collected by H. Tangestani, 5 Jun 2018.

Comparative material.

Plectorhinchus schotaf (N = 18): Gulf of Oman: ZMFUM-HA-103 to 106, four specimens, 268.9-290.9 mm, Jask, 5 Nov 2017, H. Rahmani; Persian Gulf: ZMFUM-HA-114 to 120, six specimens, 254.5-313 mm, Bushehr, 13 Apr 2018, H. Tangestani; Red Sea: BPBM 20355, 245 mm, Port Sudan, 9 Oct 1974, J.E. Randall; BPBM 20766, two specimens, 234-243 mm, Port Sudan, 14 Oct 1975, J.E. Randall; Mozambique: SAIAB 41668, four specimens, 100-121 mm, Inhaca, Sep 1948, J.L.B. & M.M. Smith; SAIAB 19796, 183 mm, Ibo, 8 Aug 1957, J.L.B. Smith.

Plectorhinchus sordidus (N = 2): Seychelles: BPBM 21661, 230 mm, Caiman Rocks, 7 Jun. 1977, J.E. Randall; Mozambique: SAIAB 41668, 81 mm, 1 Sep 1948, J.L.B. and M.M. Smith.

Diagnosis.

Plectorhinchus makranensis sp. nov. can be distinguished from other congeners by the following combination of features: (1) meristic characters: dorsal fin rays XII, 18-20; gill rakers 10-12 + 16-17 (26-29); tubed lateral-line scales 55-57; transverse scale rows above lateral line 10-11; transverse scale rows below lateral line 17-18; circumpeduncular scales 30-31; (2) morphometric characters: base of soft portion of dorsal fin 27.6-29.4% of SL; orbit diameter 25.5-30.1% of HL; caudal peduncle length 19.2-21.3% of SL; (3) Color pattern: head and body unicolor without markings, the posterior part of the opercular membrane grey; uppermost first to third pectoral-fin rays light grey.

Description.

Meristic data and morphometric data are given in Suppl. material 2: Table S2. Dorsal-fin rays XII, 18-20 (modally 19), all soft rays branched except the first; anal-fin rays III, 7-8 (rarely 8), all soft rays branched; pectoral-fin rays 16-17 (modally 16), first and second rays unbranched; pelvic rays fin I, 5, all branched; caudal fin with 9 dorsal and 7 ventral rays (total = 16), uppermost and lowermost unbranched; tubed lateral-line scales 55-57 (modally 56); scales above lateral line to the base of the first dorsal-fin spine 10-11 (modally 10); scales below lateral line to first anal-fin spine 17-18 (modally 17); circumpeduncular scales 30-31 (modally 30); gill rakers on first arch small, 10-12 on upper limb (modally 12) and 16-17 on lower limb (modally 17); branchiostegal rays 7; preopercle with 31-36 serrae.

Body elongate, moderate deep, its depth 2.8-3.4 in SL, compressed laterally and covered with ctenoid scales; scales on the middle of the body largest; lateral line extends slightly as smaller scales onto the caudal-fin base; scales present on suborbital; snout and chin without scales; predorsal scales extending through interorbital. Head moderately large, head length 3.4-3.7 in SL, upper profile convex; mouth moderately small and terminal, lips fleshy, upper jaw protruding slightly beyond the lower jaw; nostrils small, posterior nostril half diameter of anterior nostril, anterior nostril on horizontal line through the lower margin of eye; orbit diameter 3.3-3.9 in HL; three pores on each side of the chin, but no pit; teeth cardiform, approximately 2 rows laterally and 5 rows anteriorly in the upper jaw, approximately 2 rows laterally and 6 rows anteriorly in lower jaw, approximately 20-24 teeth in the upper jaw on each side and approximately 16-18 in the lower jaw on each side, palatine and vomer without teeth. Opercle with a single, exposed, short and weak spine; preopercle slightly concave and serrate, including few serrae on the posteroventral margin.

Origin of dorsal fin above the pectoral-fin base, first spine shortest, fifth spine longest, first dorsal-fin spine about 1.2 length of fifth, first spine 6.4 (6.1-6.5) in HL, fifth spine 2.6 (2.2-2.7) in HL, 6th and 7th soft dorsal-fin ray longest, 6th and 7th 3.6 in HL, 18th to 20th soft dorsal-fin ray shortest, its length 9.6-9.8 in HL, base of soft portion of dorsal fin 1.1 in base of the spinous portion; anal fin short, with somewhat rounded posterior margin, origin below base of 7th soft dorsal-fin ray, second spine longest, first ray is the longest, anal-fin length 2.5 (2.3-2.6) in HL; posterior margin of caudal fin slightly emarginate, caudal-fin length 1.7-1.8 in HL; pectoral fin reaching vertical between bases of seventh and eighth dorsal-fin spines, pectoral-fin length 1.4-1.5 in HL. Origin of pelvic fins behind pectoral-fin base, its tip reaching vertical at ninth dorsal-fin spine, second ray longest, pelvic-fin length 1.4-1.5 in HL.

Color pattern in preservative.

(Holotype: Fig. 3 ). Head and body steel grey; head and edge of fins slightly darker than the rest of the body; posterior part of opercular membrane dark grey; lips grey; ventral part of body including underside of head and belly to lower part of caudal peduncle white; iris yellow.

Color in fresh.

(paratypes: Fig. 4 ). Body silver-grey; all fins dark grey; pectoral-fin base light grey; uppermost first to third pectoral-fin rays light gray; orbital margin orange; iris grey; ventral part of body including subopercle, chest and pectoral-fin margin opaque white; lips and chin pink-grey; posterior part of opercular membrane grey.

Distribution and habitat.

The new species has been observed at six localities along the coast of the Gulf of Oman and the Persian Gulf in the Northwest Indian Ocean. Abundance was greater in the Gulf of Oman compared to the Persian Gulf. All specimens have been collected from shallow rocky and coral areas. Other species of this family which occur sympatrically at the type locality (Beris coast) with Plectorhinchus makranensis sp. nov. include: Diagramma pictum , Plectorhinchus pictus , Pomadasys kaakan , P. maculatus and P. stridens .

Etymology.

The species name is derived from the Makran coast and refers to the coastal land in southeastern Iran and southwestern Pakistan, north of the Gulf of Oman.

Multivariate analysis.

The first two Principal Components (PCs) of the meristic and morphological characters accounted for 78.3% and 60% of the variation, respectively (Fig. 5A, B ). In the meristic PCA, the number of total gill rakers, circumpeduncular scales and transverse scale rows below the lateral line loaded heavily on the first PC. Both species were completely distinguished along the first axis (Fig. 5A ). In the morphometric PCA, measurements including the length of the soft dorsal-fin base, body depth and depth of the caudal peduncle separated Plectorhinchus makranensis sp. nov. from P. schotaf along the first PC1 (Fig. 5B ).

Figures

Figure 1. Sampling localities and distribution of Plectorhinchus makranensis sp. nov. (stars), P. schotaf (squares) and P. sordidus (circles) across the Western Indian Ocean. Red star: Beris (type locality).

Figure 2. Molecular phylogenetic tree showing P. makranensis sp. nov. and other congeners based on two mitochondrial genes Cyt b and COI (total length 1672 bp). Supporting values of nodes: black circles (ML bootstrap BP ≥ 70 % and BI probability PP ≥ 0.95), orange circles on nodes support by ML (BP ≥ 70 %) but not by BI (PP ≥ 0.95), gray circles on nodes support by BI (PP ≥ 0.95) but not by ML (BP ≥ 70 %). Bar at the side of the tree represents the results of the analyses of species delimitation. Red font: sequences of this study, COI (first), Cyt b (second).

Figure 3. Holotype of Plectorhinchus makranensis sp. nov. ZMFUM-HA- 56, 246.5 mm SL, Gulf of Oman: Beris coast (Photo by E. Damadi).

Figure 4. Plectorhinchus makranensis sp. nov. a ZMFUM-HA- 205, paratype, 345.6 mm SL, Gulf of Oman: Tis coast, (Photo by E. Damadi) b ZMFUM-HA- 75, paratype, 226.6 mm SL, Gulf of Oman: Tis coast, (Photo by E. Damadi).

Figure 5. Principal components analysis (PCA) results for A meristic and B morphometric data of two species of Plectorhinchus: Plectorhinchus makranensis sp. nov. (pink); P. schotaf (green).

Figure 6. A Plectorhinchus schotaf ZMFUM-HA- 104, 268.9 mm SL, Gulf of Oman: Jask, (Photo by E. Damadi) B P. schotaf BPBM 20766, 243 mm SL, Red Sea: Port Sudan, (Photo by J. E. Randall) C P. sordidus SMF uncatalogued, 220 mm SL, Arabian Sea: Socotra, (Photo by S. V. Bogorodsky) D P. sordidus BPBM 21379, 228 mm SL, Gulf of Oman. (Photo: J. E. Randall).