Kathetostoma binigrasella, Gomon, Martin F. & Roberts, Clive D., 2011

Gomon, Martin F. & Roberts, Clive D., 2011, A second New Zealand species of the stargazer genus Kathetostoma (Trachinoidei: Uranoscopidae), Zootaxa 2776, pp. 1-12 : 5-11

Kathetostoma binigrasella sp. nov.

Banded Stargazer

Figs 3–6 ; Tbls 1–2.

Kathetostoma sp.: Paul, 1986: 118; 2000: 118; Anderson et al. 1998: unnumbered, distribution map; Roberts & McPhee, 1998: 66; Smith et al. 2006: 379, figs 1, 3, 4, molecular analysis and meristics. Roberts et al., 2009: 535, listed; Kathetostoma giganteum (non Haast, 1873): Doak, 1978: 132, colour plate 59 top.

Kathetostoma laeve (non Bloch & Schneider, 1801): Kashimoto in Amaoka et al. 1990: 298, plate 230, description.

Holotype. NMNZ P. 42147 (334) New Zealand, North Island, 11 Miles off Ninety Mile Beach, Northland, 35° 42’ S, 173° 37’ E, 100m, FV Brac, 4 July 2002, bottom trawl.

Paratypes. (31: 67.7-560): AMS I.42757-004 (316) New Zealand, West Norfolk Ridge, Wanganella Bank, 32° 36.067' S – 32° 36.067' S, 167° 34.600' E – 167° 34.517' E, 116–119m, TAN0308-112, RV Tangaroa , NORFANZ team, 30 May 2003, ratcatcher trawl; BMNH 2010.10.22.1 (244), formerly part of NMNZ P.39337; CAS 230375 (267), formerly part of NMNZ P.39337; NMNZ P.10111 (67.7) New Zealand, North Island, North Auckland, NW off Cape Reinga, 34° 3.5500' S, 172° 12.4500' E, 481–503m, JCO 8106/055, RV James Cook, 23 April 1981, trawl; NMNZ P.18175 (483) New Zealand, North Island, Bay of Plenty, Off the East side of Mayor Island, Bay of Plenty, 37° 18’ S, 176° 18’ E, 37–91m, MoNZ T86, FV Asterix, G. Nicholson & K. Smith , 17 February 1986, set net; NMNZ P.29710 (2: 305–366) New Zealand, Snares Islands, E Snares Shelf NW Campbell Plateau, 48° 18.28' S, 167° 57.25' E, 132–134m, TAN 9301/066, RV Tangaroa , 23 February 1993, bottom trawl; NMNZ P.31966 (188) New Zealand, South Island, Otago, approx. 20 nautical miles S of Dunedin, 46° 35.345' S, 167° 14.390' E, 63–66, TAN 9502/144, RV Tangaroa, P. McMillan , 10 March 1995, bottom trawl; NMNZ P.33673 (560) New Zealand, North Island, Taranaki, off the Puniho coast, SW of New Plymouth, 39° 10’ S, 173° 35’ E, 80m, J. & R. Ansley, September 1996; NMNZ P.34887 (2: 316–398) New Zealand, Chatham Islands, NE Chatham Rise, 43° 15.1450' S, 177° 4.4083' W, 310–327m, TAN 9801/030, RV Tangaroa, P. McMillan , 0 8 January 1998, bottom trawl; NMNZ P.39337 (3: 308–453) Australia, Norfolk Island, Wanganella Bank, 32° 37.200' S, 167° 35.635' E, 120–127m, NORFANZ TAN 0308/117, RV Tangaroa , 30 May 2003, ratcatcher trawl; NMNZ P.40689 (255) New Zealand, South Island, Southland, Snares Islands Shelf, 48° 49.55' S, 166° 59.30' E, 176–195m, OBS 1738/065, FV Chiyo Maru 3, Marli Dee, 20 February 2003, bottom trawl; NMNZ P.40700 (2: 157–195) New Zealand, Snares Islands, South-east Snares Shelf, 48° 49.90' S, 166° 57.75' E, 176–182m, OBS 1856/018, FV Sur Este 707, Chris Petyt, 27 January 2004, bottom trawl; NMNZ P.40701 (207) New Zealand, Snares Islands, Southern Snares Shelf, 48° 47.65' S, 166° 29.75' E, 174–190m, OBS 1856/026, FV Sur Este 707, Chris Petyt, 30 January 2004, bottom trawl; NMNZ P.41511 (324) New Zealand, Snares Islands, south eastern Snares Shelf., 48° 33.8850' S, 168° 5.6250' E, 250– 500m, TAN 0 118, RV Tangaroa , November 2001, bottom trawl; NMNZ P.41697 (146) New Zealand, South Island, Southland, North-east Puysegur Trench, 44° 57.10' S, 166° 4.35' E, 174–222m, OBS 1604/079, FV Oyang 97, 12 March 2002, bottom trawl; NMNZ P41747 (2: 128–175) New Zealand, South Island, Southland, Puysegur Bank, 46° 31.50' S, 166° 4.25' E, 185–270m, OBS 1609/052, FV Tomi Maru 86, Julian Hall, 0 2 March 2002, bottom trawl; NMNZ P.42076 (209) New Zealand, Snares Islands, South of The Snares, 48° 48.75' S, 166° 40.55' E, 180– 244m, OBS 1609/016, FV Tomi Maru 86, Julian Hall, 0 9 February 2002, bottom trawl; NMNZ P.42132 (307) New Zealand, South Island, off Stewart Island; NMNZ P.42145 (262) New Zealand, North Island, 11 Miles off Ninety Mile Beach, Northland, 35° 42’ S, 173° 37’ E, 100m, FV Brac, 0 4 July 2002, bottom trawl; NMNZ P.42146 (292) New Zealand, North Island, 11 Miles off Ninety Mile Beach, Northland, 35º 42.000' S, 173º 37.000' E, 100m, FV Brac, 0 4 July 2002, bottom trawl; NMNZ P.42153 (308) New Zealand, North Island, 11 Miles off Ninety Mile Beach, Northland, 35° 42’ S, 173° 37’ E, 100m, FV Brac, 0 4 July 2002, bottom trawl; NMV A 25153-001 (223) New Zealand, West Norfolk Ridge, Wanganella Bank, 32° 36.067' S – 32° 36.067' S, 167° 35.217' E – 167° 35.217' E, 116–122m, TAN0308-105, RV Tangaroa, M. Gomon , 29 May 2003; NMV A 25157-003 (282) same data as AMS I 42757 -004; NMV A 25161 -003 (311), New Zealand, West Norfolk Ridge, Wanganella Bank, 32° 35.783' S – 32° 35.783' S, 167° 38.550' E – 167° 41.250' E, 325–497m, TAN0308-118, RV Tangaroa, M. Gomon , 30 May 2003, ratcatcher trawl; USNM 398707 (172), formerly part of NMNZ P.40700.

Other material. NMNZ P.10111 (66.3); NMNZ P.13112 (2: 360–400); NMV A 25157-006 (197); NMV A 25161 (308).

Diagnosis. Dorsal fin rays 15–17; anal fin rays 14–16; vertebrae 30–31; head and body broad, head width 1.2– 1.7 times its length, covered with tiny blunt knobs in juveniles to almost smooth in adults; mouth with several prominent canines between smaller canines; chin smooth; 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; 17–19 gill rakers on first arch in the form of patches of fine teeth, patches broad, about six to ten teeth across patches, not in distinct rows, innermost teeth rather short; dorsal fin of moderate length, its base 43–66% of predorsal length; pelvic fins large, their length 23–28% SL; body whitish below usually with two broad, vertical, dark-brown, variously distinct bands or saddles across back, most distinct in juveniles and small adults.

Description. (See Table 2 for frequencies of values for selected meristic characters.) Dorsal fin rays 15–17; anal fin rays 14–16; pectoral fin rays 21; pelvic fin rays I, 5; vertebrae 30–31.

(See Table 1 for comparative ranges of selected proportional measurements.) Body tapering from a broad, flat, bony head (head width 1.2–1.7 times its length) covered with tiny blunt knobs in juveniles to almost smooth with fine radiating pattern 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. Scales absent; lateral line pores in skin high on side close to base of dorsal fin. Dorsal fin low, of moderate length, its base 43–66% of predorsal length. Pectoral fins huge, fan-like. Pelvic fins large, their length 23–28% SL. Largest specimen examined 560 mm SL.

Pigmentation in alcohol. Pale dusky with two broad dark blotchy bands across dorsum to midside (most distinct in juveniles and small adults; large adults more uniformly dark above), one across predorsal with paler area on dorsal midline, second across dorsal base, paler areas including side of head and chin speckled with smaller darkish blotches; top of head rather pale with darkish blotches on skin covered areas (as lines radiating from eyes in some); underside slightly dusky; dorsal, caudal and pectoral fins dark, dorsal and caudal fins with continuous pale margin; pectoral fin dark to margin centrally with pale distal margin dorsally and ventrally, anal and pelvic fins dusky, pelvics with pale margin.

TABLE 1. Selected proportional measurements and counts for Kathetostoma giganteum and types of K. binigrasella sp. nov.

Kathetostoma binagrasella sp. nov. Kathetostoma giganteum Holotype Paratypes (n=32) (n=15)

Range Mean ± SD Range Mean ± SD

Standard length (mm) 334 67.7–560 52.0–529

% SL

Meristic values

Dorsal-fin rays 15 15–17 17–19 Anal-fin rays 15 14–16 17–18 Vertebrae 30 30–31 33–34 13 14 15 16 17 18 19 28 29 30 31 32 33 34

Kathetostoma spp Dorsal Fin Rays Vertebrae

binigrasella sp.nov. 16 9 1 23 1

giganteum 1 4 6 1 11

canaster 9 7 5 1 3 12 2

laeve 3 17 6 3 13 7

nigrofasciata 2 9 3 6 Anal Fin Rays

binigrasella sp.nov. 3 23 2

giganteum 6 6

canaster 3 17

laeve 3 15 7

nigrofasciata 8 3

Fresh colours: Greenish tan above, bands brownish with scattered dark brown speckles and blotches, underside greyish white with pink tinges, dorsal, caudal and pectoral fins dark greenish brown, dorsal and pectoral speckled with brown; pelvic and anal fins dusk white with white margins.

Etymology. The specific name binigrasella , from the Latin bi for ‘two’, nigra for ‘dark’ and sella for ‘saddle’ refers to the broad dark brown saddle-like bands dorsally on the body that are obvious features distinguishing this species from its New Zealand congener.

Distribution. Widespread and relatively common in coastal and offshore waters, from the Wanganella Bank (southern Norfolk Ridge) to the Snares shelf, including the Chatham Rise. Endemic to New Zealand. Occurs at 10– 500 m depth, but more frequently taken in 100–300 m; lives on sand or mud bottoms.

Comments. Despite its recognition for more than 25 years, this species has been confused with its New Zealand congener Kathetostoma giganteum in literature and fisheries catch data. Records of New Zealand giant stargazers probably include both species, especially where capture depths are less than 400 m. Based on confirmed records, population sizes of this species are smaller than those of its congener.

A genetic study by Smith et al. (2006) implies closer relationships between the new species and the rather broadly distributed Australian Kathetostoma leave (Bloch & Schneider, 1801) , and between Kathetostoma gigantum and the southeastern Australian Kathetostoma canaster Gomon & Last, 1987 , than the two New Zealand congeners are to one another. This is consistent with differences in morphology ( Table 2) and depth distributions of the four, with K. binigrasella and K. leave having relatively few vertebrae (30–31 and 28–31 respectively) and anal fin rays (14–16 and 13–15), shorter and chunkier bodies, smaller eyes, prominent broad banded colour patterns and shallower depth ranges, and K. canaster and K. giganteum having more vertebrae (31–33 and 33–35 respectively) and anal fin rays (15–16 and 17–19), more elongate and slender bodies, larger eyes, more obscure banding, if banding is at all apparent, and distributions to greater depths (to 700 and over 1000m respectively). Genetics of the fifth Australasian species K. nigrofasciatum confined to the outer portion of the continental shelf and top of the slope in southwestern Australia supports a common ancestry with the ancestor of all four. That species has even lower meristic values, which overlap partially with those of B. binigrasella and B. leave , as well as a distinctly banded pattern that may be more indicative of the ancestral condition than a relationship between the species, as at least the banded colouration is found in other uranoscopid genera as well.

Figures

FIGURE 3. Kathetostoma binigrasella sp. nov.: A, NMNZ P. 10111, 67.7 mm SL, juvenile, dorsal view of head and lateral view of body (illustrated by R. Plant); and B, holotype, NMNZ P. 42147, 334 mm SL, adult, dorsal and lateral views (illustrated by M. Freeborn).

FIGURE 4. Kathetostoma binigrasella sp. nov., paratype, NMV A 25153 - 001, 223 mm SL, New Zealand, West Norfolk Ridge, Wanganella Bank, 32 ° 36.067 ' S – 32 ° 36.067 ' S, 167 ° 35.217 ' E – 167 ° 35.217 ' E, 116 – 122 m, TAN 0308 - 105, RV Tangaroa, M. Gomon, 29 May 2003, dorsal and lateral views.

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.