Galathea aculeata Haswell, 1882

Macpherson, Enrique & Robainas-Barcia, Aymee, 2015, Species of the genus Galathea Fabricius, 1793 (Crustacea, Decapoda, Galatheidae) from the Indian and Pacific Oceans, with descriptions of 92 new species, Zootaxa 3913 (1), pp. 1-335 : 26-28

Galathea aculeata Haswell, 1882

( Fig. 4 )

Galathea aculeata Haswell, 1882a: 761 (Holborn Island and Port Molle, Queensland, 36 m. — Haswell, 1882b: 162.— Grant & McCulloch, 1906: 48, pl. 4, figs 4, 4a (Holborn Island and Port Molle, Queensland).

Dubious identifications

Galathea aculeata Henderson, 1888: 120 (off Manila and off Nukalofa, Tongatabu, 33 m).— Whitelegge, 1900: 190 (no record).— Tirmizi, 1966: 178, figs 3, 4A (Red Sea, 29–55 m).— McNeill, 1968: 33 (Great Barrier Reef, Lizard Island, 16–37 m).— Lewinsohn, 1969: 111 (no record).— Johnson, 1970: 4, fig. 1a (Shoal west of Pulau Pawai, Singapore, 9 m).— Haig, 1973: 280 (off Double Island Point, Queensland, 31 m).— Haig, 1974: 447 (Western Australia).— Poupin, 1996: 19 (compilation of French Polynesia records).

Material examined. Type material (syntypes). Australia. Queensland, Port Molle, 20.33°S, 148.85°E, 36 m, Coll. W.A. Haswell: 1 F 4.3 mm (AM P267), 1 F 3.6 mm, dry specimen (AM G5657). Queensland, Holborn Island, Port Denison, 1 specimen, 1 dry specimen (glued to glass), 4.5 mm (AM P41003).

Description. Carapace: Slightly longer than broad; cervical groove laterally bifurcated; ridges on gastric and anterior branchial regions scale-like or in concentric arcs; epigastric region with 2 submedian spines; 1 hepatic and 1 parahepatic spines, and 1 anterior branchial spines on each side. Mid-transverse ridge laterally interrupted, preceded by cervical groove, followed by 4 ridges, 2 of them uninterrupted. Lateral margins slightly convex medially, with 8 spines: 2 spines in front of and 6 spines behind anterior cervical groove; first anterolateral, second small, located at midlength between first spine and anterior cervical groove; 3 spines on anterior branchial margin, and 3 spines on posterior branchial margin, last smaller than others; additional spine ventral to between first and second lateral spine. External limit of orbit with small spine; infraorbital margin with 1 spine. Rostrum moderately elongate, triangular, 1.7 times as long as broad, 0.6 carapace length and breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.3 distance between proximalmost lateral incisions; dorsal surface with short setiferous ridges; lateral margin with 4 deeply incised sharp teeth.

Pterygostomian flap unarmed.

Sternum: Plastron about as long as broad, lateral extremities gently divergent posteriorly.

Abdomen: Somites 2–3 each with 2 transverse ridges on tergite, with or without additional interrupted ridges between, anterior ridge more distinctly elevated than posterior ridge; tergite of somite 4 with anterior ridge only; somites 5 and 6 without ridges, posteromedian margin of somite 6 nearly transverse. No males examined.

Eyes: Ocular peduncles 1.5 times longer than broad, maximum corneal diameter 0.7 rostrum width.

Antennule: Article 1 with 3 well-developed spines, distodorsal larger; distomesial spine somewhat smaller and more slender than distolateral. Ultimate article with tuft of fine setae on distodorsal margin.

Antenna: Article 1 with distomesial spine exceeding distal margin of article 2. Article 2 with 2 well-developed distal spines. Articles 3 and 4 unarmed.

Mxp3: lacking or not observable in syntypes examined.

P1: 3.0 times carapace length, with sparse long plumose setae. Merus 1.0 times length of carapace, 1.9 times as long as carpus. Carpus 0.9 length of palm, 2.1 times as long as broad. Palm 2.1 times as long as broad, lateral and mesial margins slightly divergent; spines arranged in irregular rows, dorsolateral row of spines continued onto whole lateral margin of fixed finger. Fingers 1.1 times palm length; mesial margin of movable finger with 4 small proximal spines; each finger distally with 2 rows of teeth, spooned.

P2–4: Moderately slender, with long sparse plumose setae. Meri successively shorter posteriorly (P3 merus 0.9 length of P2 merus, P4 merus 0.9 length of P3 merus); P2 merus 0.7 carapace length, 2.9 times as long as broad, 1.2 times longer than P2 propodus; P3 merus 2.9 times longer than broad, equally broad as P4 merus, 1.1 times longer than P3 propodus; P4 merus 2.9 times as long as broad, 1.0 length of P4 propodus. Propodi subequal in length, each about 4 times as long as broad; extensor margins each with 3–4 spines on proximal half in P2 and P3, with 1 proximal spine in P4; flexor margins each with 6 or 7 slender movable spines. Dactyli subequal in length, 0.7 length of propodi; flexor margins each with 5 proximally diminishing teeth bearing minute robust setae.

Epipods on P1–3.

Color. Unknown.

Remarks. Galathea aculeata had been synonymized with G. subsquamata Stimpson, 1858 (cf. Baba et al. 2008). Both species belong to a group of species characterized by scale-like ridges on the gastric region, and the branchial region with dorsal spines. However, they are easily differentiable by the presence or absence of postcervical spines on the carapace (see Remarks of G. subsquamata ). The existence of some new species belonging to this group also suggests that numerous records identified as G. aculeata or G. subsquamata need revision and probably belong to the closely related species (e.g., G. acerata n. sp., G. polydora n. sp.). Galathea aculeata most closely resembles G. peitho n. sp. from Japan to Australia (see Remarks of this species).

No molecular data is available from G. a c u l ea t a.

Distribution. Australia, Queensland, Holborn Island and Port Molle, 36 m. Other literature records under the name G. aculeata need revision, as noted above.

Figures

FIGURE 4. Galathea aculeata Haswell, 1882, syntype, female 4.3 mm, Australia, Queensland (AM-P 267). A, carapace and abdomen, dorsal view; B, anterior pterygostomian area, lateral view; C, thoracic sternites 3 and 4; D, left part of cephalothorax, ventral view, showing antennular and antennal peduncles, and anterior part of pterygostomian flap; E, right P 1, dorsal view; F, right P 2, lateral view; G, right P 3, lateral view; H, right P 4, lateral view (setae on appendages not figured). Scale: A, F – H = 1 mm; E = 2 mm; B – D = 0.5 mm.