Agononida incerta ( Henderson, 1888 )

Ahyong, Shane T. & Poore, Gary C. B., 2004, Deep-water Galatheidae (Crustacea: Decapoda: Anomura) from southern and eastern Australia, Zootaxa 472 (1), pp. 1-76 : 8-9

Agononida incerta ( Henderson, 1888)

Munida incerta Henderson, 1888: 130 , pl. 13, fig. 4a [type locality: off Sibago Island, Philippines].

— Baba et al., 1986: 171, 290, fig 121; 1988: 106; 1994: 12. — Macpherson, 1994: 478, fig. 74; 1996: 394.

? Munida incerta . — Baba, 1994: 12.

Munida sp. cf. squamosa . — Jones & Morgan, 2002: 135 [colour plate].

Agononida incerta . — Baba & de Saint Laurent, 1996: 442. — Macpherson, 1997: 600, 602; 1999: 413. — Davie, 2002: 59.

Material examined. Form­a. NEW SOUTH WALES: AM P49277, 1 male (29.5 mm), 65 km E of Sydney , 457 m, S. Leonard, 17 Feb 1997 ; AM P42274, 1 female (22.0 mm), NE of Sugarloaf Point , 32º15’S, 153º02’E, 427 m, K78­03­04, 5 Apr 1978 ; AM P31486, 1 male (30.0 mm), E of Batemans Bay , 33º45’S, 150º36’E, 270 m, K77­03­04, Apr 1977 ; AM P21761, 1 female (37.8 mm), SE of Clarence River , 29°41–32’S, 153°45–47’E, 414 m, K75­09­04, 10 Oct 1975 ; AM P21690, 2 males (33.0– 34.8 mm), SE of Clarence River , 29°41–32’S, 153°45–47’E, 414 m, K75­09­04, 10 Oct 1975 ; AM P21012, 1 female (24.1 mm), E of Broken Bay , 33°25–30’S, 152°03–07’E, 641 m, K75­05­04, 19 Aug 1975 ; AM P46658, 1 female (29.4 mm), off Tweed Heads , 28°10’S, 153°33’E, 600 m, N. Coleman, Jun 1978 ; AM P42282, 1 ovigerous female (22.5mm), NE of North Solitary Island , 29°48’S, 153°43’E, 430 m, K78­16­07, 2 Aug 1978 ; AM P31495, 2 males (28.0– 36.7 mm), 3 females (20.9–31.8 mm), NE of North Solitary Island , 29°38’S, 153°47’E, 470 m, K78­23­15, 7 Nov 1978 ; AM P31496, 1 ovigerous female (33.0 mm), NE of North Solitary Island , 29°32’S, 153°48’E, 412 m, K78­16­03, 2 Aug 1978 ; AM P31427, 1 ovigerous female (36.2 mm), NE of Wooli , 29°47–49’S, 153°44–43’E, 437 m, K78­16­07, 2 Aug 1977 ; AM P67306, 1 male (32.2 mm), E of Wooli , 29°52’S, 153°43’E, 495 m, K77­13­10, 23 Aug 1977 .

Form­b: QUEENSLAND: AM P42262, 8 males (14.4–35.1 mm), 8 females (22.5– 36.6 mm), NE of Tweed Heads , 27°57’S, 154°03’E, 548 m, beam trawl, K78­23­09, 6 Nov 1978 .

NEW SOUTH WALES: AM P31429, 2 males (33.0–35.0 mm), 2 females (25.4–34.0 mm), SE of Cape Byron , 28°42’S, 153°51’E, 150 m, K78­17­21, 18 Aug 1978 .

Remarks. The present series includes two forms, both identifiable with A. incerta . Form­a corresponds to those reported by Baba (1994) from north Queensland by having the “pronounced outward process on the anterior lateral expansion of the telson” in males, and relatively slender, subcylindrical chelae in which the merus lacks a ventral row of spines. Sexual dimorphism of the chelae in form­a is slight and no gape is present between the dactylus and pollex. Form­b lacks the lateral process on the telson margins in males, and the chelae are more robust, prismatic in cross­section with more strongly rugose surfaces, and a row of 2–4 small spines on the lower margin of the merus. Sexual dimorphism of the chelae in adult males of form­b is pronounced such that a distinct gape is present between the dactylus and pollex. In addition, the chelae are more robust in form­b such that the palm is markedly more inflated in form­b females than in either sex of form­a. Similar morphological variation was observed by Macpherson (1994) between specimens from various Indo­West Pacific localities. Colour patterns of the two forms are also probably different. Live specimens of form­a are a pale­cream colour with a red band across the distal portion of the dactylus, propodus and merus of the walking legs, and a red band across the articulations of the chelipeds. A specimen of form­a from northwestern Australia is figured in colour by Jones & Morgan (2002: 135) as Agononida sp. cf. squamosa . Conversely, a specimen of A. incerta that appears to correspond to form­b, figured in colour by Baba et al. (1986: 170), has a reddish overall colouration without banding across the pereopods. Unfortunately, the holotype of A. incerta is a female and lacks chelae ( Henderson 1888). Other Philippine specimens, however, are reported to have subcylindrical chelae ( Macpherson 1994) suggesting that form­b might be referable to A. incerta sensu stricto. The two forms almost certainly represent distinct species but are not further treated here owing to ongoing study of the species by Keiji Baba (Kumamoto University, Japan).

Distribution. Western Indian Ocean to Indonesia, the Philippines, Japan, the central Pacific, and eastern Australia; 17–720 m (summarised by Macpherson 1994).