Forsterygion capito ( Jenyns, 1841 )

Jawad, Laith A., 2008, Second revision of the New Zealand triplefin genus Forsterygion Whitley and Phillips, 1939 (Pisces: Tripterygiidae), Journal of Natural History 42 (47 - 48), pp. 2943-2989 : 2962-2965

Forsterygion capito ( Jenyns, 1841)

Mottled triplefin

Tripterygion capito Jenyns 1841, p. 94 –95, pl. 19, Fig. 1 ; Richardson 1844, p. 212.

Tripterygium nigripenne (non Valenciennes in Cuvier and Valenciennes (1836)) Gunther 1861, p. 277.

Tripterygium nigripenne (non Valenciennes in Cuvier and Valenciennes (1836)) Hutton 1872, p. 31.

Tripterygium jenningsi Hutton 1879, p. 339 –340; Hardy 1990, p. 14.

Tripterygion robustum (non Clarke, 1879); Hutton 1890, p. 280; Gill 1893, p. 119; Doak 1972, p. 103; Ruck 1973, p. 1–10; Paulin and Stewart 1985, p. 51; Hardy 1989, p. 491; Roberts 1991, p. 33.

Tripterygion varium (non Forster in Bloch and Schneider (1801)) Waite 1909, p. 597– 598 (Musgrave Harbour, Auckland Islands); Thomson 1913, p. 230; Waite 1913, p. 7; Graham 1938, p. 416 (Otago Harbour).

Enneapterygius mortenseni Rendahl 1926, p. 11 –12; Nielson 1974, p. 74 (type in Zoologisk Museum Copenhagen).

Tripterygion nigripenne (non Valenciennes in Cuvier and Valenciennes (1836)) Darby 1966, p. 192–195.

Tripterygion nigripenne robustum (non Clarke, 1879) Darby 1966, p. 192–195.

Forsterygion nigripenne (non Valenciennes in Cuvier and Valenciennes (1836)) Anderson 1973, p. 3, 99 (Leigh).

Gilloblennius (?) sp. Hardy 1986b, p. 29 (Snares Islands: Hono Bay, 15m).

Forsterygion nigripenne robustum (non Clarke, 1879) Mayr and Berger 1992, p. 243– 256 (Territoriality, microhabitat selection).

Forsterygion ? robustum (non Clarke, 1879) Paulin and Roberts, 1992, p. 93–94, Figs 45 a, b, pl. 16 D–F.

Grahamina capito: Fricke and Roberts, 1993, p. 6 –11, Figs 4–6 ( New Zealand).

Diagnosis

A species of Forsterygion with the following set of characters: sloping snout profile, concave or (rarely) steep. Line from tip of premaxilla continued beyond ventral margin of orbit crossing preoperculum or touching its dorsal extremity. No groove in front of first dorsal fin, although medial sensory pore sits at base of depression; nape naked or with superficial or embedded cycloid scales.

Dorsal fin formula V-0N-0-1-0-1 (35). Nine procurrent rays in upper lobe, seven in lower lobe; in upper caudal lobe, one large ray between upper lobe and posterior epural, six rays opposite epurals, one ray opposite neural spine of third preural vertebra, one ray anterior to neural spine of third preural vertebra; in lower caudal lobe, six rays opposite haemal spine of second preural vertebra, one ray opposite haemal spine of third preural vertebra.

Description

The following counts and proportions (given as times in standard length unless otherwise stated) are based on 128 non-type specimens of 31–90mm SL. F. capito differs from F. varium in the following combination of characters: Inter orbit flat. Snout profile sloping, concave or (rarely) steep. No groove in front of first dorsal fin, although medial sensory pore sits at base of depression. Supraorbital tentacles usually, consisting of two branches sometimes ranging from three to seven. Medium-size species. First dorsal fin low. Pectoral fin almost reaching to base of third to sixth anal fin membrane.

Head length 4.2–4.5; predorsal length 5.9–6.5; preanal length 2.5–2.6; peduncle length 4.6–5.2; peduncle depth 15.3–16.4; pectoral fin length 4.5–4.6; eye diameter 3.3–3.5 in HL; upper jaw length 2.3–2.5 in HL; snout length 3.3–3.4 in HL.

First dorsal fin spines V–VII; second dorsal fin spines XVIII–XXI; third dorsal fin rays 13–15; pectoral fin rays 14–18; anal fin rays I–II, 24–27. Discontinuous lateral line with 16–21 tubular scales, 16–26 notched scales. Total vertebral number 43–45.

Head sensory canals. Postocular canal extending beyond supratemporal canal. Supratemporal canal with few, small sensory pores. Preoperculo-mandibular canal broad, with discontinuous anterior line of sensory pores. No sensory papillae on frontal, temporal and upper part of otic canals. Ventral part of preoperculomandibular canal with six pores, three at base of preoperculum, two between tip of upper jaw and one at lower jaw symphysis. No sensory papillae.

Squamation. Head, nape, and base of pectoral fin naked. Most of post-temporal margin devoid of scales except for embedded cycloid scales at base of first dorsal fin. Anterior scale margin crenate. Secondary radii present in scales from all body regions. Nine to thirteen radii and long ctenii on scales under lateral line. Denticles on inter-radial circuli, short, narrow and only found in scales from caudal peduncle and base of caudal fin. Rounded, complete focus field, with fine and coarse bumps on inner region.

Osteology. Post-temporal smooth, not exposed. Ossified, incomplete inter-orbital septum. Lacrimal with rough ventral and smooth orbital edges. Small club-shaped basihyal. Basibranchials close together, third basibranchial elongated, with long, broad anterior end. First hypobranchial curved. Three to four rows of teeth on ventral side of fifth ceratobranchial. Oppositely arranged, unstalked gill rakers. Epibranchials straight, first epibranchial with phalanges directed anteriorly and posteriorly, third with an extension at distal end reaching fourth element. Three to five rows of teeth on ventral side of infrapharyngobranchial. Usual inverted-boat shaped urohyal (lateral view), short side. Poorly developed and non-elevated basibranchial attachments. Single spine in anal fin of some specimens. One free pterygiophore between second and third dorsal fins. Dorsal fin formula V-0N-0-1-0-1 (35). Dorsal edge of upper hypural and ventral edge of lower hypural straight. Parhypural with rounded end. Short, broad neural spine. Straight epurals with similar width. Nine procurrent rays in upper caudal lobe, seven in lower lobe; in upper lobe, one large ray between upper lobe and posterior epural, six rays opposite epurals, one ray opposite neural spine of third preural vertebra, one ray anterior to neural spine of third preural vertebra; in lower lobe, six rays opposite haemal spine of second preural vertebra, one ray opposite haemal spine of third preural vertebra.

Otolith. Lateral surface smooth. Narrow cauda. Ostio-caudal differentiation absent. Crista inferior absent. Dorsal depression absent. Broad well-developed antirostrum.

Colour. Colour pattern highly variable. Head and body yellowish, whitish or brownish grey, with darker speckling, spotting, mottling or banding. Banded fish have five dark bands on the upper sides; mottled fish have about nine bands or blotches. Occasionally, some individuals have an extended mottling pattern surrounding eye, covering the upper lip and reaching dorsal edge of pre-operculum and operculum. In some other individuals, anterior part of head is plain without visible mottling.

Size. 91mm SL.

Distribution

Throughout New Zealand, from Northland to the Sub-Antarctic Islands (Auckland and Antipodes Islands ), including the Chatham Islands. Sheltered coastal reefs and rock and shell substrata in bays and harbours. Found from intertidal pools to at least 12m.

Material examined

Museum specimens (n 5128): NMNZ P. 1489, 4, 79.1–82.3mm SL, Enderby Island, Auckland Islands , 17 Mar 1954 ; NMNZ P. 13491, 24, 34.8–56.5mm SL., Portobello, Otago Harbour , 45 ° 509S 170 ° 399E, 13 Aug 1962 ; NMNZ P. 10663, 1, 72.4mm SL, Oamaru , 1963 ; NMNZ P. 16952, 5, 34–82mm SL, Elizabeth Island, Fiordland , 28 Feb 1985 ; NMNZ P. 16955, 5, 36–64mm SL, Elizabeth Island, Fiordland , 9 Mar 1985 ; NMNZ P. 17083, 5, 72.7–82.4mm SL, Antipodes Islands , 8 Mar 1985 ; NMNZ P. 18137, 5, 61–72mm SL., Kawaroa, New Plymouth, 39 ° 03.49S 174 ° 03.79E, 24 Jan 1986 ; NMNZ P. 19857, 1, 86mm SL, Edwardson Sound (west bank), Fiordland , 9 May 1986 ; NMNZ P. 20111, 1, 55mm SL, Charnley Island, Auckland Islands , 3 Jun 1986 ; NMNZ P. 20112, 4, 64–78mm SL, Charnley Island, Auckland Islands , 3 Jun 1986 ; NMNZ P. 20546, 1, 62.8mm SL (Lectotype of T. jenningsi ), Ewing Island, Auckland Island , Jan 1989 ; NMNZ P. 24135, 7, 31–73mm SL, Islet Cove, Port Pegasus, Stewart Island , 25 Jan 1989 ; NMNZ P. 24362, 9, Limestone Bay, Kaikoura , 7 May 1989 ; NMNZ P. 24135, NMNZ P. 24135, 7, 31–73mm SL, Islet Cove, Port Pegasus, Stewart Island , 25 Jan 1989 . Auckland University specimens: 5, 56– 66mm SL., Tinopai Wharf, Kaipara Harbour , 11 Apr 1998 ; 6, 36– 46mm SL., Whangateau Wharf, Whangateau Estuary , 13 Dec 1999 ; 3, 51.2–56.7mm SL., Orapiu Wharf, Waiheke Island , 29 Dec 1999 ; 15, 51.9– 68.3mm SL, Orapiu Wharf, Waiheke Island , 30 Dec 1999 ; 7, 34.1–82.8mm SL, Island Bay , Wellington, 7 and 8 Jan 2000 ; 5, 57.3–73.3mm SL., Seatoun Wharf , Wellington, 8 Jan 2000 ; 6, 46.5–62.8mm SL, Akaroa Wharf, Akaroa , 31 Aug 2001 ; 3, 30.3–35.4mm SL, Terror Cove, Auckland Islands , 24 May 2002 .

Figures

Figure 1. SEM micrograph of F.varium scale showing the straight annulus at the inter-radial area. Scale bar5200 Mm.

Figure 4. Gill arches, with gill rakers removed of F. varium (left side only shown). BH, basiyal; BB, basibranchials (three ossified, one cartilaginous shown stippled); CB, ceratobranchials (five); EB, epibranchials (four); HB, hypobranchials (three); IPB, infrapharyngo-branchial plate. Scale bar51 mm.

Figure 5. Ventral view of the urohyal bone of F. varium. Scale bar51mm.

Figure 6. Caudal skeleton of F. varium (procurrent rays in black). NS, neural spine; HS, haemal spine; HY, hypural; PH, parhypural; U, urostyle. Scale bar51 mm.