Acentronura tentaculata Günther, 1870

Short, Graham A. & Trnski, Thomas, 2021, A New Genus and Species of Pygmy Pipehorse from Taitokerau Northland, Aotearoa New Zealand, with a Redescription of Acentronura Kaup, 1853 and Idiotropiscis Whitley, 1947 (Teleostei, Syngnathidae), Ichthyology & Herpetology 109 (3), pp. 806-835 : 823

publication ID	https://doi.org/ 10.1643/i2020136
DOI	https://doi.org/10.5281/zenodo.5827740
persistent identifier	https://treatment.plazi.org/id/99248794-CA3B-F41A-CA97-44308DD3F952
treatment provided by	Diego
scientific name	Acentronura tentaculata Günther, 1870
status

Treatment

Acentronura tentaculata Günther, 1870 View in CoL

Figures 8C–D View Fig , 9C–D View Fig , 11B View Fig ; Tables 2–4 View Table 2 View Table 3 View Table 4

Acentronura tentaculata Günther, 1870: 516 View in CoL (Suez, Egypt).

Syngnathoides algensis Fourmanoir, 1954: 210 View in CoL (Dzaoudzi, Mayotte Island, Commore Island).

Acentronura mossambica Smith, 1963: 522 View in CoL , pl. 76, figs. f, g (Inhaca and Inhambane Estuary, Mozambique).

Diagnosis.— See generic diagnosis. Acentronura tentaculata differs from its congeners by the following combination of characters: supraoccipital consists of distinct bony bipartite dorsomedial crest, segments arcuate in lateral view, followed by an elevated and bony dimple; posterior margin of second segment of dorsomedial crest located at opening of, but not merged within, the bony dimple, which is approximately equal in length to the dorsomedial crest and tapered posteriorly.

Description.— Morphometric and meristic characters listed in Tables 2–4 View Table 2 View Table 3 View Table 4 . Superior trunk and tail ridges discontinuous below dorsal-fin base, lateral tail ridge present, inferior trunk ridge ends at anal ring, lateral trunk ridge confluent with inferior tail ridge. Head angled ventrally 25° from the principal body axis, the anterodorsal profile slightly conoid in lateral aspect; supraoccipital, low, not elevated, with a distinct bony bipartite dorsomedial crest, segments arcuate in lateral view, followed by an elevated and bony dimple; posterior margin of second segment of dorsomedial crest located at opening of, but not merged within, the bony dimple, which is approximately equal in length to the dorsomedial crest and tapered posteriorly; bilateral bony lobed protuberances on the posterolateral margins of the post-temporal bones ( Fig. 10C View Fig ); anterior nuchal plate absent ( Fig. 9C–D View Fig ); posterior nuchal plate present anterior to cleithrum with dorsomedial crest-like ridge along its dorsum, large gap present between the supraoccipital and posterior nuchal plate; small blunt spine midway between orbit and lobed protuberance on operculum; cleithral ring distinct, discontinuous mid-dorsally; single gill slit between supraoccipital and cleithral ridge; rim of orbit projecting dorsolaterally and slightly ventrolaterally; snout spine absent; interorbital narrow, depressed; opercular ridge distinct, entire, angled dorsally toward gill opening; swelling of gular region ventroposterior to orbit absent; pectoral-fin base without distinct ridges, low, strongly elevated ventrolateral bulge supporting the pectoral-fin absent; trunk deepest anteriorly, principal body ridges distinct; principal body ridge spines absent; caudal fin absent. Acentronura tentaculata exhibits strong sexual dimorphism associated with the presence of a male brood pouch. The brood pouch is formed along the ventral midline of the tail and is present below the anteriormost 12 tail rings ( Fig. 8C–D View Fig ). µCT scanning of the material ( Fig. 9C–D View Fig ) revealed the brood pouch is enclosed by 12 arcuate bony extensions, which extend ventrolaterally from the anterior ventral plate ridges of the tail and are reduced in size posteriorly. The anteriormost pouch plate is broad and paddle-shaped at ventrocaudal margin and curved posterolaterally relative to other pouch plates. The posteriormost pouch plate is diminutive in size.

Distribution.— Acentronura tentaculata is known from the tropical Indo-West Pacific, from East Africa, Madagascar, the Red Sea, Arabian and Persian gulfs to Torres Strait, Philippines, the northern Great Barrier Reef, Australia, and New Caledonia ( Dawson, 1985; Rivaton and Richer de Forges, 1990; McKenna, 2003; Fricke and Kulbicki, 2006; Al-Jufaili et al., 2010; Grandcourt, 2012; Nakae et al., 2018).

Material examined.— Acentronura tentaculata: CAS 247139, male, 50.8 mm SL, female, 53.9 mm SL, Tamaraw Beach, South Puerto Galera, Philippines, 13°30'03.8'' N, 120°53 ' 40.2 '' E, Hearst Philippine Biodiversity Expedition, station PG-011, B. Moore and H. Hamilton, 3 June 2011.