Acentronura tentaculata Gunther 1870
Creators: name: Short, Graham A.
name: Trnski, Thomas
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Syngnathiformes
Syngnathidae
Acentronura
Acentronura tentaculata

description: Acentronura tentaculata Günther, 1870
Figures 8C–D, 9C–D, 11B; Tables 2–4
Acentronura tentaculata Günther, 1870: 516 (Suez, Egypt).
Syngnathoides algensis Fourmanoir, 1954: 210 (Dzaoudzi, Mayotte Island, Commore Island).
Acentronura mossambica Smith, 1963: 522, 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. 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); anterior nuchal plate absent (Fig. 9C–D); 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). µCT scanning of the material (Fig. 9C–D) 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.
description: Published as part of 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), pp. 806-835 in Ichthyology & Herpetology 109 (3) on page 823, DOI: 10.1643/i2020136, http://zenodo.org/record/5827826