Galathea multicristata , 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: 200-202

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-FF34-42EF-FF6D-FE9907BCE94A

treatment provided by

Plazi

scientific name

Galathea multicristata
status

n. sp.

Galathea multicristata  n. sp.

( Fig. 72View FIGURE 72)

Material examined. Holotype: New Caledonia. BATHUS 4, Stn CP889, 21°00.83'S, 164 ° 27.34 'E, 416–433 m, 2 August 1994: M 7.4 mm (MNHN-IU- 2013-8324).

Etymology. From the Latin, multi, numerous, and crista, ridge, crest, in reference to the numerous ridges on the dorsal surface of the carapace.

Description. Carapace: as long as broad; transverse ridges with dense short setae, and a few scattered long plumose setae; cervical groove distinct, laterally bifurcated. Dorsal surface with numerous interrupted and scalelike ridges, and only mid-transverse and posterior ridge uninterrupted. Three pairs of small epigastric spines; 2 or 3 small hepatic spines on each side. Lateral margins well convex medially, with 10 spines: 2 spines in front of and 8 spines behind 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, with spine ventral to between first and second; 4 spines on anterior branchial region, second larger than others, and 4 spines on posterior branchial margin, last small. Small frontal spine between lateral limit of orbit and first anterolateral spine; infraorbital margin with 3 spines. Rostrum 2.3 times as long as broad, triangular, length 0.7 postorbital carapace length and breadth 0.3 that of carapace; distance between distalmost lateral incisions 0.25 distance between proximalmost lateral incisions; dorsal surface nearly horizontal in lateral view, with numerous scale-like setose ridges; lateral margin with 5 deeply incised sharp teeth.

Pterygostomian flap rugose, unarmed, ridges with short setae, anterior margin bluntly angular.

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

Abdomen: Somites 2–4 each with 3 or 4 uninterrupted or medially interrupted transverse ridges on tergite; somite 5 with 2 uninterrupted ridges; somite 6 with 2 medially interrupted ridges, posteromedian margin slightly convex. Males with G 1 and G 2.

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

Antennule: Article 1 with 3 well-developed distodorsal and distolateral spines, distodorsal larger; distomesial spine well-developed, smaller than others. Ultimate article with a few short fine setae not in tuft on distodorsal margin.

Antenna: Article 1 with ventral distomesial spine nearly reaching distal margin of article 2. Article 2 with 2 well-developed distal spines, distolateral spine slightly larger than distomesial and reaching end of article 3. Articles 3 and 4 unarmed.

Mxp 3: Ischium with well-developed spine on flexor distal margin; extensor margin unarmed; crista dentata with 27 denticles. Merus shorter than ischium; flexor margin with 2 spines, proximal clearly longer than distal; extensor margin with distal spine. Carpus unarmed.

P 1: 3.8 times carapace length, somewhat depressed on palm, more so on fingers, covered with finely setiferous scales, with numerous long plumose and non-plumose setae. Merus 1.3 times length of carapace, 2.0 times as long as carpus, with spines arranged roughly in rows, dorsomesial spines stronger; distal spines prominent. Carpus 0.7 length of palm, 1.6 times as long as broad; dorsal surface with some small spines; mesial margin with 4 spines (distal second strong). Palm 1.7 times as long as broad, lateral and mesial margins slightly divergent; small spines arranged roughly in dorsolateral and dorsomesial rows. Fingers 0.8 length of palm, each finger distally with two rows of teeth, spooned; fingers unarmed.

P 2–4: moderately slender, with setose striae and numerous long plumose and non-plumose setae. P 2 twice carapace length. Meri successively shorter posteriorly (P 3 merus 0.8 length of P 2 merus, P 4 merus 0.7 length of P 3 merus); P 2 merus 0.8 carapace length, 4.5 times as long as broad, 1.4 times longer than P 2 propodus; P 3 merus 4.1 times longer than broad, 1.2 times longer than P 3 propodus; P 4 merus 2.8 times as long as broad, 0.9 length of P 4 propodus. Extensor margin of P 2–3 meri with row of 11–13 proximally diminishing spines, and 5 spines on P 4; flexor margins distally ending in strong spine followed proximally by 0–1 spines and several eminences; distoflexor angle of P 2–4 with one small and one well-developed spines; lateral sides unarmed on P 2–3, and with 5 or 6 small spines on P 4. Carpi with 5 or 6 spines on extensor margin on P 2–4; lateral surface with 2 or 3 small spines or acute granules sub-paralleling extensor margin on P 2–4; flexor distal margin with spine. P 2–4 propodi 4.6 –5.0 times as long as broad; extensor margin with 2–4 proximal spines on P 2–4; flexor margin with 5 or 6 slender movable spines on P 2–4. Dactyli subequal in length, distally ending in well-curved strong spine, length 0.5 that of propodi; flexor margin with 5 or 6 proximally diminishing teeth, terminal one prominent.

Epipods present on P 1.

Remarks. Galathea multicristata  n. sp. is closely related to G. ciliosa  n. sp. from Vanuatu from which it can be distinguished by the following characters:

- The hepatic region has two or three spines in G. multicristata  , being unarmed in G. c i l i o s a. - The carapace surface has numerous scale-like ridges in G. multicristata  , but only a few ones are present in G. ciliosa  .

- The proximal spine on the flexor margin of the Mxp 3 merus is clearly larger than the distal spine in G. multicristata  , and subequal in G. ciliosa  .

No genetic data are available for G. multicristata  . Distribution. New Caledonia, 416– 433 m.