Kathetostoma giganteum Haast, 1873

Gomon, Martin F. & Roberts, Clive D., 2011, A second New Zealand species of the stargazer genus Kathetostoma (Trachinoidei: Uranoscopidae), Zootaxa 2776, pp. 1-12 : 3-5

Kathetostoma giganteum Haast, 1873

Giant Stargazer

Figs 2 , 5 , 6 : Tbls 1–2.

Kathetostoma leave (non Bloch & Schneider, 1801): Hutton, 1872: 23, Wellington Harbor.

Kathetostoma giganteum Haast, 1873 : Trans. Proc. New Zeal. Inst. 5: 274, pl. 16 (second from top), Heathcote estuary, NZ; holotype: CMC.

Kathetostoma giganteum: Waite, 1911: 241 ; Waite & McCulloch, 1915: 471; Phillipps, 1921: 123, listed; Phillipps, 1927: 43; Mees, 1960: 47, 56; Whitley, 1968: 69, listed; Ayling & Cox, 1982: 271, pl. 35; Paul, 1986: 118; Francis, 1988: 48, pl. 116; Paul, 2000: 118; Kashimoto in Amaoka et al. 1990: 297, pl. 229, description; Anderson et al. 1998: unnumbered, distribution map; Smith et al. 2006: 379, figs 1, 3, 4, molecular analysis and meristics; Roberts et al., 2009: 535, listed.

Material examined (17: 52.0-529). NMNZ P.1286 (105), NMNZ P.10376 (529), NMNZ P.30702 (78.3), NMNZ P.30818 (4: 72.2–195), NMNZ P.38774 (104), NMNZ P.40882 (277), NMNZ P.40883 (227), NMNZ P.40884 (422), NMNZ P.41212 (52.0), NMNZ P.41739 (3: 110–123), NMNZ P.42067 (503), NMNZ P.42081 (314).

Diagnosis. Dorsal fin rays 17–19; anal fin rays 17–18; vertebrae 33–34. Body rather elongate, tapering from a moderately broad, flat, bony head (head width 1.1–1.4 times its length) covered with tiny blunt spines in juveniles ( Fig. 2 A) to low radiating ridges in adults; eyes directed upwards, small; bony orbital rim separated medially by naked rectangular space; mouth large, vertical, with several prominent canines between smaller canines; chin smooth; lips with short ridge-like crenulations; ventral margin of preopercle with four spine-like processes; anterior end of isthmus with a pair of prominent forward directed spines; prominent cleithral spine sheathed with skin above pectoral fin base; 14–17 gill rakers on first arch in the form of patches of fine teeth, patches narrow, teeth in three or four rows, innermost row rather long; scales absent; lateral line pores in skin high on side close to base of dorsal fin; dorsal fin low, elongate, its base 67–82% of predorsal length; pectoral fins huge, fan-like; pelvic fins moderately large, their length 20–25% SL. (See Table 1 for a summary of proportional measurements and meristic values.)

Maximum size of specimens examined 650 mm SL, but reported in the literature as reaching 850 mm ( Francis 2001).

Pigmentation in alcohol. Juveniles dark overall with lengthwise, often irregular pale stripes, one at base of dorsal fin extending onto nape. Slightly larger individuals rather uniformly dark dorsum extending to posterior end of dorsal fin with narrow lengthwise white stripe following lateral line onto caudal fin and shorter stripes above and below anterior to dorsal fin; white markings smaller and more irregular in larger juveniles; dark area reaching ventrally to lateral midline only below posterior end of dorsal fin and above pectoral fin; underside pale; top of head mottled pale and dark; caudal peduncle very pale; dorsal, caudal and pectoral fins dark with pale distal margins; anal and pelvic fins pale. Large adults rather uniformly dark with some darker speckles and mottling; pale lateral line becoming less apparent.

Fresh colours. Mottled dark greenish brown and tan above with scattered dark brown to black speckles and blotches, pale areas, especially around lateral line, almost white, underside greyish white with pink tinges, dorsal caudal and pectoral fins dark greenish brown, dorsal and pectoral speckled with brown; pelvic and anal fins dusky white with white margins.

Distribution. Endemic to New Zealand, distributed widely in coastal, shelf and offshore waters, including Chatham Rise, Lord Howe Rise and Campbell Plateau; the record from Tasmanian waters ( Scott, 1974; 1980) is incorrect and a misidentification of specimens of K. canaster . Occurs at a wide range of depths from shallow estuaries to more than 1000 m on the upper slope with the species’ greatest abundance at 200– 400 m.

Comments. Kathetostoma fluviatilis Hutton, 1972 , based on a 1.7 inch juvenile collected in fresh water of the Manawatu River, may be an earlier name for this species. The type is apparently no longer extant. Although Hutton’s brief description more closely matches the species described below, descriptions of uranoscopids by early authors have proven to be unreliable, especially with fin ray counts. As neither of New Zealand’s species of Kathetostoma has been adequately documented in fully freshwater conditions, questions remain about the true identity of the species. It is therefore regarded as a nomen dubium.

Figures

FIGURE 2. Kathetostoma giganteum: A, NMNZ P. 1286, 105 mm SL, juvenile, dorsal view of head and lateral view of body (illustrated by R. Plant); and B, NMNZ P. 42067, 503 mm SL, adult, dorsal view of head and lateral view of body (illustrated by M. Freeborn).

FIGURE 5. Comparison of length of dorsal fin base and predorsal length relative to size in specimens of Kathetostoma binigrasella sp. nov. and K. giganteum examined.

FIGURE 6. Comparison of pelvic fin length and standard length relative to size in specimens of Kathetostoma binigrasella sp. nov. and K. giganteum examined.