Galathea australiensis Stimpson 1858

Galathea australiensis Stimpson, 1858

(Fig. 13)

Galathea australiensis Stimpson, 1858: 89 (Port Jackson, 11 m).— Haswell, 1882b: 161 (Port Jackson and Port Stephens).— Henderson, 1888: 118, pl. 12, fig. 5 (Arafura Sea, 90 m).— Grant & McCulloch, 1906: 44, pl. 4, figs 1, 1a (Mast Head Island, Queensland).— Southwell, 1906: 220 (Sri Lanka S of Galle, off Kaltura, coral reefs in Gulf of Manaar, shallow water to 183 m).— Stimpson, 1907: 230 (Port Jackson, 11 m).— Hale, 1927: 78, fig. 74 (no record).— Lewinsohn, 1967: 180, figs 1–13 (Port Jackson, 5.5 m).— McNeill, 1968: 33 (Great Barrier Reef, Low Island, subtidal).— Haig, 1973: 277 (Cliffy I. off Corner Inlet, Victoria and Spencer Gulf, South Australia, 29 m).— Haig, 1974: 446 (no record).— Davie, 2002: 60 (no record).— Poore, 2004: 232, fig. 63f, pl. 13d (compilation).—Baba et al., 2008: 65 (compilation).— Poore et al., 2011: 332, pl. 10A (color photo, southern Australia).

Not Galathea australiensis.— Yokoya, 1933: 57 (Suruga Bay and SE of Tsushima, 51–110 m) =? Galathea balssi Miyake & Baba, 1964.

Dubious identifications:

Galathea australiensis.— Ortmann, 1892: 251, pl. 11, figs 8, 8a, 8i (Amami-oshima, Ryukyu Islands).— Borradaile, 1900: 421 (Lifu, Loyalty Islands).— De Man, 1902: 710 (Ternate).— Southwell, 1906: 220 (Sri Lanka S of Galle, off Kaltura, coral reefs in Gulf of Manaar, shallow water to 183 m).— Balss, 1913b: 2 (Red Sea).— Laurie, 1926: 123 (Amirante, Saya De Malha Bank, Cargados Carazos, 37–146 m).— Melin, 1939: 56, figs 32–35 (Port Lloyd, Taninoura and Kopepe Bay (Bonin Islands)).— Miyake & Baba, 1966a: 60, figs 3–5 (Ishigaki-jima, Okinawa-jima, Amami-oshima, intertidal).— Tirmizi & Javed, 1993: 55, fig. 24 (Indian Ocean).

Material examined. Australia. New South Wales. Port Jackson, 33.85°S, 151.27°E: 2 M 3.4–4.5 mm, 4 ov. F 4.4–5.3 mm (AM-P269).—NE Bass Point, The Humps, 34.59286°S, 150.90611°E, 23.5 m, 3 May 2010, 1 M 3.3 mm (AM-P83431).

Australia. Queensland. Bramton Islands, intertidal, 5 May 2009: 1 F 3.5 mm (SMF 3635).

Australia. Victoria. E Bass Strait, Cruise 83-54-1, Stn 209, 38°18'S, 147°37'E, 55 m, 31 September 1993: 12 M 2.3–3.4 mm, 18 F 2.4–3.0 mm (NMV-J13358).

Description. Carapace: As long as broad; transverse ridges with numerous short fine setae and a few long thick plumose setae; setae non iridescent; cervical groove laterally bifurcated. Gastric region with 9 ridges: 2 epigastric ridges, sometimes medially interrupted, with 2 submdian spines, posterior ridge scale-like; 2 protogastric ridges, anterior one medially convex, uninterrupted and laterally reaching second lateral marginal spine, without parahepatic spine, posterior ridge uninterrupted; 2 mesogastric ridges, anterior ridge uninterrupted, not continuing laterally to anterior branchial region, posterior ridge scale-like; 3 metagastric ridges, anterior ridge uninterrupted and continuing laterally to lateral marginal, following ridge scale-like, posteriormost ridge moderately short. Hepatic spine absent. Mid-transverse ridge uninterrupted, preceded by cervical groove. Posterior branchial region with 6 or 7 transverse ridges. Lateral margins convex medially, with 8 spines: 2 spines in front of and 6 spines behind anterior cervical groove; first (anterolateral) moderately strong, second small, located at midlength between first spine and anteriormost spine of branchial margin, additional spine ventral to between first and second lateral spines; 3 spines on anterior branchial margin, and 3 spines on posterior branchial margin, last small. External limit of orbit with small spine subequal to anterolateral spine; infraorbital margin with 1 spine. Rostrum 1.5 times as long as broad, length 0.5 of postorbital carapace length and breadth 0.3 of carapace width, nearly horizontal in lateral view; distance between distalmost lateral incisions 0.3 distance between proximalmost lateral incisions; dorsal surface with small setiferous ridges; lateral margin with 4 deeply incised sharp teeth, each bearing stiff long setae on mesial base (setae not figured).

Pterygostomian flap rugose, with facial spine on anterior part, anterior margin spiniform.

Sternum: 0.8 times as long as broad, lateral extremities gently divergent posteriorly.

Abdomen: Somites 2–3 each with 3 or 4 transverse uninterrupted ridges on tergite, anterior ridge more distinctly elevated than posterior ridge; tergite of somite 4 with 2 interrupted and 2 uninterrupted transverse ridges placed alternately; somites 5 with 2 uninterrupted or medially interrupted ridges; somite 6 with 2 medially interrupted ridges, posteromedian margin straight. Males with G1 and G2.

Eyes: Ocular peduncles 1.1–1.3 times longer than broad, maximum corneal diameter 0.6 rostrum width.

Antennule: Article 1 with 3 spines; well-developed distodorsal and distolateral spines, distodorsal larger; distomesial spine also well-developed, slightly shorter than distolateral. Ultimate article moderately elongate, twice longer than broad, without fine setae on distodorsal margin.

Antenna: Article 1 with strong distomesial spine not reaching distal margin of article 3. Article 2 with 2 subequal well-developed distal spines, overreaching midlength of but not reaching end of article 3. Article 3 unarmed.

Mxp3: Ischium with well-developed distal spine on flexor margin; flexor margin with small but distinct distal spine; crista dentata with 17–19 denticles. Merus slightly shorter than ischium; flexor margin with 2 subequal welldeveloped spines; extensor margin with 1 distal spine. Carpus unarmed.

P1: 2.4–2.6 (females), 3.0–3.4 (males) times postorbital carapace length, relatively slender, subcylindrical, somewhat depressed in palm, more so in fingers; scales setose, with scattered long thick plumose setae (not figured). Merus as long as carapace, 1.5–2.0 times as long as carpus, with spines arranged in longitudinal rows, distal spines prominent. Carpus 0.6–0.9 length of palm, 2.0–2.5 times as long as broad; dorsal surface with small spines arranged in longitudinal rows; mesial margin with 1 or 2 strong spines, distal second largest. Palm 3.0–3.2 times longer than broad, lateral and mesial margins subparallel; spines arranged in longitudinal rows, some small spines scattered on dorsal side. Fingers 0.6–0.8 length of palm, each finger distally with 2 rows of teeth, spooned; some spines along lateral margin of fixed finger, mesial margin of movable finger with minute proximal spines.

P2–4: moderately slender, with setose striae and long sparse plumose setae (not figured). Meri successively shorter posteriorly (P3 merus 0.9 length of P2 merus, P4 merus 0.9 length of P3 merus); P2 merus 0.7 of carapace length, 2.9 times as long as broad, 1.1 times longer than P2 propodus; P3 merus 3.3 times longer than broad, 1.2 times longer than P3 propodus; P4 merus 3.1 times as long as broad, 1.2 length of P4 propodus; extensor margins each with row of 6–10 proximally diminishing spines in P2–4; lateral surfaces unarmed; flexor margins distally ending in strong spine in P2–3 followed proximally by small spine and several tubercles or transverse ridges. Carpi each with 4 or 5 spines on extensor margin in P2–3, 1 or 2 spines in P4; lateral surface with small spines subparalleling extensor margin in P2–4; flexor distal margin with small spine. Propodi 4.5 (P2), 4.0 (P3) and 3.5 (P4) times as long as broad; extensor margins each with 3 proximal spines in P2–3; flexor margins each with 5–7 movable spines in P2–4. Dactyli subequal in length, distally ending in noticeably curved strong spine, 0.5–0.7 length of propodi; flexor margins each with prominent triangular subterminal tooth followed by 5–7 low teeth.

Epipods present on P1–3.

Remarks. Galathea australiensis seems to be restricted to Australian waters and records from other areas should be revised. The presence of epipods on P1–3, 1 facial spine on the pterygostomian flap, 2 anterolateral marginal spines on the carapace, and 3 well-developed terminal spines on the antennular basal article, are the main characters to distinguish G. australiensis from the other species.

Galathea australiensis resembles G. corallicola Haswell 1882 from Australia and Papua New Guinea, but they can be easily distinguished by the presence of epipods on the P 1–3 in G. australiensis, instead only on the P 1 in G. corallicola.

No molecular data are available from G. australiensis.

Distribution. Australia, Queensland, New South Wales, Victoria, at depths of 5– 55 m.