Galathea homologa , Macpherson, Enrique & Robainas-Barcia, Aymee, 2015

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: 139-140

publication ID

http://dx.doi.org/10.11646/zootaxa.3913.1.1

publication LSID

lsid:zoobank.org:pub:18D06EC6-A61D-4C45-9B5E-52435903556D

persistent identifier

http://treatment.plazi.org/id/03B3F979-FF79-42AD-FF6D-FDC1072EEADA

treatment provided by

Plazi

scientific name

Galathea homologa
status

n. sp.

Galathea homologa  n. sp.

( Fig. 47View FIGURE 47)

Material examined. Holotype: Vanuatu. SANTO, Stn DB1, 15° 33.1 'S, 167 ° 17.8 'E, 15–25 m, 10 September 2006: F 3.0 mm (MNHN- IU- 2013-8050).

Etymology. From the Greek homologos, agreeing, in reference to the close relationship with the G. aegyptiaca  species group.

Description. Carapace: Slightly broader than long; anterior cervical groove indistinct. Five ridges on gastric region: 1 epigastric ridge with 2 median epigastric spines, medially interrupted; 1 protogastric ridge strongly convex medially, uninterrupted, with 1 parahepatic spine at each side; 1 mesogastric ridge uninterruptedly extending laterally to anteriormost of branchial marginal spines; 2 uninterrupted metagastric ridges, anterior ridge sometimes fused with anterior branchial ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, usually followed by 5 ridges. Lateral margins medially convex, with 7 spines: 2 spines in front of, and 5 spines behind, indistinct anterior cervical groove; first anterolateral, well-developed, at same level of lateral limit of orbit; second, small, at midlength between anterolateral spine and anteriormost spine of branchial margin, accompanying another spine ventral to between first and second; 2 spines on anterior branchial region, and 3 spines on posterior branchial margin, last small. External limit of orbit ending in small spine; infra-orbital margin with strong spine. Rostrum broad triangular, 1.3 times as long as broad, length 0.6 that of, breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.25 distance between proximalmost lateral incisions, dorsal surface nearly horizontal in lateral view, with some thick long plumose setae; lateral margin with 4 sharp spines. Ridges with numerous unirramous setae, and some thick long plumose setae between epigastric spines and on median convexity of second gastric ridge.

Pterygostomian flap rugose, anterior margin ending in well-developed spine.

Sternum: As long as broad, lateral limits divergent posteriorly.

Abdomen: Somites 2–4 each with 2 uninterrupted transverse ridges on tergite; somite 5 and 6 each with 2 medially interrupted ridges, posteriomedian margin of somite 6 slightly convex.

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

Antennule. Article 1 with 3 well-developed distal spines, distodorsal larger. Ultimate article short, twice longer than broad, with tuft of setae on distodorsal margin.

Antenna. Article 1 with depressed ventral distomesial process slightly exceeding distal margin of peduncle. Article 2 with distomesial spine as long as distolateral, exceeding midlength of article 3. Articles 3 and 4 unarmed.

Mxp 3. Ischium with well-developed distal spine on flexor margin; extensor margin unarmed; crista dentata with 22 denticles. Merus slightly shorter than ischium, with 2 strong spines of subequal size on flexor margin, proximal one located at midlength, distal one at terminal end; extensor margin with distal spine. Carpus spineless.

P 1: missing.

P 2–4: Relatively slender, moderately setose, with long plumose setae on all articles. P 2 1.7 times carapace length. P 2–3 meri subequal in length, P 4 merus 0.9 length of P 3 merus, equally broad on P 2–4. P 2 merus 0.7 carapace length, 3.3 times as long as broad, 1.5 times longer than P 2 propodus; P 3 merus 3 times as long as broad, 1.3 times length of P 3 propodus; P 4 merus 3 times as long as broad, 1.2 length of P 4 propodus. Extensor margins with row of 8 or 9 proximally diminishing spines on P 2–3, only distal spine on P 4; lateral surface unarmed on P 2–3, row of 4 spines on P 4; flexor margins with strong terminal spine; ventromesial margin with terminal spine on P 2–3. Carpi with 3 or 4 spines on extensor margin; lateral surface with row of 2–4 small spines paralleling extensor row; flexor distal margins with small spine. Propodi subequal in length on P 2 and P 4, slightly longer on P 3, equally broad on P 2–4, each about 4 times as long as broad; extensor margin with 2 or 3 proximal spines on P 2–4; flexor margin with 4 slender movable spines on P 2–4; lateral side unarmed on P 2–4. Dactyli subequal in length, 0.5–0.6 length of propodi, ending in incurved, strong, sharp spine; flexor margin with prominent triangular terminal tooth preceded by obsolescent 4 teeth.

Epipods present only on P 1.

Remarks. The species is close to G. aegyptiaca  and G. corbariae  n. sp. (see Remarks for these species).

Distribution. Vanuatu, 15– 25 m.