Uroptychus australis, (HENDERSON, 1885)

Schnabel, Kareen E., 2009, A review of the New Zealand Chirostylidae (Anomura: Galatheoidea) with description of six new species from the Kermadec Islands, Zoological Journal of the Linnean Society 155 (3), pp. 542-582 : 551-553

UROPTYCHUS AUSTRALIS ( HENDERSON, 1885)

Diptychus australis Henderson, 1885: 420 [part, specimens from Challenger stn 164 and male from Challenger stn 194A] [type locality: off Port Jackson, New South Wales, Australia, 34° 8′S, 152° 0′E, 950 m, 12.vi.1874, Challenger stn 164, lectotype designated by Baba (2005)].

Uroptychus australis . – Henderson, 1888: 179, pl. 21: fig 4a–c. – Thomson, 1899: 197 (list). – Ahyong & Poore, 2004: 18, fig. 3. – Poore, 2004: 224, fig. 60. – Baba, 2005: 224 (list).

Not Uroptychus australis Henderson, 1885 [paralectotypes from Challenger stns 170 & 171 and female from Challenger stn 194A]. (= Uroptychus spp. ).

Type material: 1 ♂ (6.2 mm), lectotype, off Port Jackson , 34° 8′S, 152° 0′E, 950 m, 12.vi.1874, Challenger stn 164 ( BMNH 1888 : 33) . 1 ♀ ovig (10.0 mm), 1 ♀ (10 mm), paralectotypes, type locality ( BMNH 1888 : 33) . 1 ♂ (6.9 mm), paralectotype, off Banda , 4° 31.0′S, 129° 57.2′E, 958 m, 29.ix.1874, Challenger stn 194A (1/2) ( BMNH 1888 : 33) .

Other material examined: Reinga Basin : 1 ♂ (8.0 mm), 2 ♀ (7.2, 8.8 mm), 35° 19.99′S, 172° 19.99′E, 1029–1074 m, 22.iii.1968, NZOI stn E880 ( NMNZ Cr. 012078). Kermadec volcanic arc: 1 ♀ (10.0 mm), 1 ♀ ovig. (8.38 mm), 29° 51.70′S, 178° 10.90′W, 965– 1008 m, 27.vii.1974, NZOI stn K831 ( NMNZ Cr. 012079). 2 ♀ (4.1, 4.3 mm), 30° 36.49′S, 178° 22.50′W, 1030 m, 30.vii.1974, stn K861 ( NIWA 23053 ). 1 ♂ (7.4 mm), 30° 01.89′S, 178° 48.06′W, 872–1086 m, 23.iv.2002, RV Tangaroa , stn TAN0205/73 ( NIWA 18585 ). 1 ♂ (10.0 mm), 33° 10.24′S, 179° 58.20′W, 999– 643 m, 16.iv.2002, RV Tangaroa , stn TAN0205/32 ( NIWA 18592 ). Hikurangi Plateau: 2 ♀ (10.0, 11.1 mm), 37° 34.00′S, 179° 22.00′E, 1395 m, 6.iii.1969, stn D836 ( NIWA 23052 ). Hikurangi Trough: 1 ♀ (10.0 mm), 39° 28.56′S, 178° 25.29′E, 874 m, 3.vi.1999, RV Kaharoa, stn KAH9907/38 ( NIWA 18582 ). Chatham Rise: 4 ♂ (10.3–11.7 mm), 4 ♀ (7.1–10.5 mm), 3 ♀ ovig. (8.8, 10.0, 10.8 mm), 37° 34.00′S, 179° 22.00′E, 1395 m, 6.iii.1969, NZOI stn D836 ( NMNZ Cr. 012080) .

Diagnosis: Carapace excluding rostrum distinctly longer than broad; lateral margins unarmed, subparallel, posterior quarter with low ridge; dorsum unarmed or with pair of small epigastric tubercles. Rostrum sharply triangular. Sternal plastron wider than long along midlength; sternite 3 strongly depressed, anterior margin narrow; deeply emarginated, with pair of median spines. Antennal basal article with distinct outer spine; ultimate and penultimate articles unarmed; antennal scale slightly shorter to slightly longer than peduncle. Pereopod 1 (cheliped) merus with at least one row of large tubercles on inner proximal margin; ischium with stout triangular distodorsal spine. Pereopods 2–4 with proximal portion of the merus dorsal ridge with irregular margin; carpi smooth along dorsal margin; pereopods flexor margin with terminal spines paired, closely followed by penultimate spine and close to juncture with dactylus; dactyli with spines on flexor margin orientated parallel to dactylar margin; length of P4 merus about half that of P3.

Variation: The new records agree with the illustrations by Ahyong & Poore (2004) with only minor variations: most specimens bear a pair of epigastric tubercles but in about 10% of the specimens, these are absent (one specimen from NZOI station D836 NMNZ Cr. 012080 bears an additional minute tubercle).

The antennal scale is more commonly just short of the antennal peduncle but about 25% of the specimens bear an antennal scale slightly overreaching the antennal peduncle. Large tubercles on the inner margin of the merus are mostly arranged in two short longitudinal rows but may only comprise very few tubercles in small specimens although large males show this character most clearly.

Remarks: Uroptychus australis closely resembles Uroptychus empheres Ahyong & Poore, 2004 , Uroptychus gracilimanus ( Henderson, 1885) , Uroptychus vandamae Baba, 1988 , and Uroptychus remotispinatus Baba & Tirmizi, 1979 but is distinct from these in the combination of having the antennal scale longer or slightly shorter instead of distinctly shorter than the antennal peduncle, sternite 4 lacking a field of granules and the anterolateral spine falling short of the anterior margin of sternite 3, large tubercles on the proximal flexor margin of the cheliped merus, in having the P4 merus about half instead of two-thirds as long as that of P3, the spines on the flexor margin of the P2–4 orientated parallel to, instead of oblique to the dactylar margin.

Henderson’s (1885) type material, from four Challenger stations amongst Indonesia (male and female), Port Jackson (male and two females), and the Kermadec Islands (two females), include three species of which Baba (2005) designated the male from Challenger stn 164 (Port Jackson) as lectotype. The female from Challenger stn 194 (off Banda, Indonesia) and the specimens from Challenger stns 170 and 171 (Kermadec Islands) belong to a different and undescribed species Uroptychus sp. (see below). Uroptychus australis differs from this species in e.g. lacking distinct epigastric spines, the antennal scale nearly reaching or overreaching the antennal peduncle and having inclined spines along the dactylar flexor margin of the walking legs nearly contiguous with the margin.

Distribution: This is a widespread south-west Pacific species, currently known from eastern Australia, New Zealand, and Indonesia, at depths of 458–1395 m ( Fig. 5 ).

Specimens from NZOI station D836 ( NMNZ Cr. 012080) were preserved with pieces of gorgonian coral indicating a possible association of this species with coral.

Figures

Figure 5. Records of Uroptychodes spinimarginatus (Henderson, 1885), Uroptychus alcocki Ahyong & Poore, 2004, Uroptychus australis (Henderson, 1885), Uroptychus novaezelandiae Borradaile, 1916, Uroptychus maori Borradaile, 1916, Uroptychus politus (Henderson, 1885), Uroptychus scambus Benedict, 1902, and Uroptychus sp. around New Zealand. Solid symbols indicate type records. 250, 1000, and 2500 m bathymetric contours are shown.