Plectranthias winniensis (Tyler)

Gill, Anthony C., Pogonoski, John J., Moore, Glenn I. & Johnson, Jeffrey W., 2021, Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species, Zootaxa 4918 (1), pp. 1-116 : 103-105

Plectranthias winniensis (Tyler)

Figures 18 , 43 ; Tables 1–16, 24

Common name: Redblotch Perchlet

Pteranthias winniensis Tyler 1966: 2 , fig. 1 (type locality: Saint Joseph Atoll, Amirante Group, Seychelles).— Paxton et al. 1989: 507 (checklist).— Allen et al. 2006: 991 (checklist).— Randall 1996: 129 (Bougainville Reef, Coral Sea).— Anderson 2018: 34 (checklist). — Parenti & Randall 2020: 31 (checklist).

Diagnosis. The following combination of characters distinguishes P. winniensis from all known congeners: dorsal rays X,15–17; fourth dorsal spine longest; pectoral rays 16–18, all unbranched; 2–3 enlarged antrorse serrations on ventral edge of preopercle; lateral line complete, interrupted or incomplete, consisting of 14–28 + 0–3 tubed scales; and greatest body depth 29.1–32.6 % SL.

Remarks. A relatively small species (largest specimen 40 mm SL; Heemstra & Randall 2009), P. winniensis was originally described from the Seychelles, western Indian Ocean, but has since been recorded from widely throughout the Indo-Pacific, from the Red Sea to the Pitcairn and Hawaiian Islands ( Randall 1980, Heemstra 1996, Heemstra & Randall 2009). In Australia, it is known from the northern Great Barrier Reef and reefs in the adjacent Coral Sea ( Figure 18 ). However, P.C. Heemstra (in Williams et al. 2013) noted that specimens from the western Indian Ocean differ in live coloration from those from French Polynesia, and it is possible that there are at least two species involved. Our use of the name for Australian specimens is therefore tentative.

We add the following new observations: scales with peripheral cteni; vertebrae 10+16; supraneurals 3; predorsal formula 0/0+0/2/1+1; dorsal pterygiophores in interneural spaces 9–13 1/1/1+1/1+1/1+1 or 1/1/1+1/1+1+1/1; no trisegmental pterygiophores associated with dorsal fin; terminal dorsal pterygiophore in interneural space 17–18; no trisegmental pterygiophores associated with anal fin; terminal anal pterygiophore in interhaemal space 5–6; ribs present on vertebrae 3 through 10; epineurals present on vertebrae 1 through 11; parhypural and hypurals autogenous; well-developed hypurapophysis on parhypural; epurals 3; single uroneural (posterior uroneural absent); ventral tip of cleithrum with well-developed posteroventral process; proximal tip of first anal-fin pterygiophore near distal tips of parapophyses on vertebra 10.

Morphometric data are summarised in Table 24.

This species is relatively distinctive in having the following combination of characters: dorsal rays X,15–17; fourth dorsal spine longest; pectoral rays 16–18, all unbranched; and two enlarged antrorse serrations on ventral edge of preopercle. Only one other species approaches this character combination, P. ahiahiata Shepherd, Phelps, Pinheiro, Pérez-Matus & Rocha, 2018 , described from the holotype from Rapa Nui (Easter Island). The authors noted that, of species surveyed, mtDNA COI sequence data for P. ahiahiata was closest to P. winniensis (12.3% uncorrected differences). The two species differ in number of dorsal-fin rays (X, 18 in P. ahiahiata versus X, 15–17 in P. winniensis ), tubed lateral-line scales (lateral line complete with 31 tubed scales versus complete, interrupted or incomplete with 14–28 + 0–3 tubed scales) and live coloration.

Material examined. Queensland, Australia. AMS I.22584-026, 30.8 mm SL, Great Barrier Reef , Escape Reef North, outer barrier, 15 o 49′S, 145 o 50′E, 30–42 m , AMS party, 29 Oct 1981 ; AMS I.22620-014, 30.9 mm SL, Great Barrier Reef , Escape Reef, 15°49′S, 145°50′E, 38–40 m, G . R. Allen , W. Starck & A. Ayling, 3 Nov 1981 . New Caledonia. AMS I.47353-051, 3: 22.3–28.8 mm SL , AMS I.47353.059, 2: 23.8-24.2 mm SL (subsequently cleared and stained), northwest side of Walpole Island , 22°36.08′S 168°56.73′E, 23–29 m, SWP Ichthyology team, 29 Jul 2017 . Vanuatu. AMS I.37304, 32.6 mm SL, Erromango Island , south side of Dillon′s Bay, north shore of Wilson′s Point, 18°49.65′S, 169°00.38′E, 25–29 m, M. McGrouther et al., 24 May 1996 . Cook Islands. AMS I.46733-033, 39.6 mm SL, Nieu Beveridge Reef , west side of atoll, 19°59′S, 167°45′W, 18–23 m, S.E. Reader, 5 Jan 2015 .

Additional specimens identified for distribution information. Australia. AMS I.25107-072, 28.5 mm SL, Coral Sea , Osprey Reef, west edge dropoff (13°56′S 146°34′E), 10–25 m , AMS team, 6 Nov 1984 ; WAM P.28541- 038, 4: 21–30 mm SL, Coral Sea , Holmes Reef, 16°31′S, 147°50′E, 12–14 m, G . R. Allen, 20 Nov 1985 ; WAM P.28537-008, 3: 21–27 mm SL, Coral Sea , Herald Cays, 17°00′S, 149°07′E, 15–25 m, G . R. Allen, 17 Nov 1985 .

Figures

FIGURE 18. Distribution records for Plectranthias ferrugineus n. sp. (closed circles; arrow indicates type locality), P. kamii (open circles; Australian records only, excluding Christmas Island) and P. winniensis (triangles; Australian records only).

FIGURE 43. Plectranthias winniensis: A) BPBM 13528, 40.0 mm SL, freshly dead, Tomoe Atoll, Tuamotu Archipelago, French Polynesia; B) AMS I.22584-026, 30.8 mm SL, preserved, Escape Reef North, Great Barrier Reef, Australia. Photos by J.E. Randall (A) and A.C. Gill (B).