Galathea cymo, 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 : 96-99

Galathea cymo n. sp.

( Figs 30 , 116 E)

Material examined. Holotype: Vanuatu. SANTO, Stn DB86, 15°38.5'S, 167°15.1'E, 13 m, 4 October 2006: M 3.6 mm (MNHN-IU-2013-13327).

Paratypes: Vanuatu. SANTO, Stn DB16, 15°35.5'S, 167°15.8'E, 32–40 m, 14 September 2006: 4 M 3.0– 3.4 mm, 4 ov. F 2.7–3.0 mm, 1 F 2.7 mm (MNHN-IU-2013-13351); 1 F 2.5 mm (MNHN-IU-2013-13352); 1 F 2.6 mm (MNHN-IU-2013-13353).—Stn NB12, 15°33.1'S, 167°09.6'E, 20 m, 19 September 2006: 1 M 2.3 mm (MNHN- IU-2013-13346).—Stn DB61, 15°32.3'S, 167°16.9'E, 41 m, 25 September 2006: 2 M 2.4–4.3 mm (MNHN-IU- 2013-13342); 1 ov. F 4.0 mm (MNHN-IU-2013-13343).—Stn DB69, 15°24.4'S, 167°13.0'E, 38 m, 27 September 2006: 4 M 1.4–2.5 mm, 3 ov. F 1.9–3.6 mm, 6 F 1.5–2.5 mm (MNHN-IU-2013-13344).—Stn NB43, 15°35.6'S, 167°16.0'E, 6–30 m, 4 October 2006: 1 ov. F 2.4 mm, 1 F 3.8 mm (MNHN-IU-2013-9767).—Stn ZR12, 15°36.7'S, 167°02.0'E, 2–30 m, 5 October 2006: 2 M 3.3–4.4 mm (MNHN-IU-2013-13349).—Stn DS91, 15°33.7'S, 167°08.4'E, 7 m, 6 October 2006: 1 F 2.0 mm (MNHN-IU-2013-13348).—Stn ZB24, 15°31.4'S, 167°14.1'E, 26 m, 12 October 2006: 1 ov. F 3.2 mm (MNHN-IU-2013-13350).—Stn EP36, 15°33.1–33.3'S, 167°12.4–12.7'E, 20–60 m, 15 October 2006: 1 M 2.6 mm, 1 F 2.0 mm (MNHN-IU-2013-13345).—Stn NB12, 15°33.1'S, 167°09.6'E, 20 m, 19 September 2006: 10 M 1.8–3.9 mm, 10 ov. F 2.2–3.4 mm, 1 F 2.4 mm (MNHN-IU-2013-13347).

New Caledonia. Chesterfield Islands. CORAIL 2, Stn DW33, 19°25'S, 158°52'E, 52 m, 23 July 1988: 1 M 2.3 mm (MNHN-IU-2013-13357).—Stn DW35, 19°22'S, 158°53'E, 52 m, 23 July 1988: 2 ov. F 3.8–5.1 mm (MNHN- IU-2013-13358).—Stn DW70, 19°15'S, 158°27'E, 54 m, 25 July 1988: 1 ov. F 3.9 mm (MNHN-IU-2013- 9778).—Stn DW77, 19°12'S, 158°36'E, 60 m, 25 July 1988: 1 ov. F 4.7 mm (MNHN-IU-2013-13354); 1 F 4.3 mm (MNHN-IU-2013-13355).—Stn DW94, 19°06'S, 158°50'E, 36–53 m, 27 July 1988: 1 M 3.5 mm (MNHN-IU- 2013-13359). Stn CP124, 19°29'S, 158°20'E, 53–56 m, 29 July 1988: 3 M 4.5–5.1 mm (MNHN-IU-2013- 13362).—Stn DW143, 19°37'S, 158°25'E, 45 m, 30 July 1988: 1 ov. F 3.7 mm (MNHN-IU-2013-13361). Lagon East, Stn 608, 22°10.7'S, 167°01.3'E, 50–56 m, August 1986: 1 M 3.7 mm, 1 ov. F 4.4 mm (MNHN-IU-2013- 13360).—Stn 612, 22°08.9'S, 167°00.5'E, 46–48 m, August 1986: 1 M 4.4 mm, 1 ov. F 4.6 mm (MNHN-IU-2013- 13371).—Stn 623, 22°01'S, 166°5.5'E, 32–40 m, August 1986: 1 ov. F 4.2 mm (MNHN-IU-2013-9773).—Stn 625, 21°59.2'S, 166°53.6'E, 34–40 m, August 1986: 1 ov. F 4.7 mm (MNHN-IU-2013-13365).—Stn 631, 21°58.3'S, 166°47.6'E, 43 m, August 1986: 1 ov. F 5.4 mm (MNHN-IU-2013-13366).—Stn 635, 21°57.7'S, 166°44.5'E, 45–52 m, August 1986: 1 M 5.1 mm (MNHN-IU-2013-9779).—Stn 637, 21°56.5'S, 166°42.1'E, 60-65 m, August 1986: 1 M 4.9 mm (MNHN-IU-2013-9775).—Stn 639, 21°55.5'S, 166°44.1'E, 48–50 m, August 1986: 2 M 5.3–5.6 mm (MNHN-IU-2013-13367).—Stn 641, 21°53'S, 166°43'E, 50–52 m, August 1986: 3 M 5.1–5.3 mm, 1 ov. F 4.8 mm (MNHN-IU-2013-13368).—Stn 642, 21°54.2'S, 166°42.2'E, 44–47 m, August 1986: 1 M 6.0 mm (MNHN-IU- 2013-9768).—Stn 651, 21°48'S, 166°36.4'E, 48 m, August 1986: 3 M 4.8–5.6 mm, 1 ov. F 4.4 mm (MNHN-IU- 2013-13372).—Stn 657, 21°48.2'S, 166°38.2'E, 42 m, August 1986: 1 M 4.7 mm, 1 ov. F 4.2 mm (MNHN-IU- 2013-13369).—Stn 658, 21°46.5'S, 166°35.2'E, 49–51 m, August 1986: 1 M 4.8 mm (MNHN-IU-2013- 9774).—Stn 659, 21°45.3'S, 166°33.4'E, 46-48 m, August 1986: 1 M 5.3 mm (MNHN-IU-2013-13373).—Stn 660, 21°46.6'S, 166°32.5'E, 48–52 m, August 1986: 1 M 3.4 mm (MNHN-IU-2013-9777).—Stn 661, 21°45.9'S, 166°41.4'E, 32 m, August 1986: 1 F 5.1 mm (MNHN-IU-2013-9771).—Stn 662, 21°44.0'S, 166°32.0'E, 50 m, August 1986: 2 M 4.5–5.8 mm, 2 ov. F 3.7–4.3 mm (MNHN-IU-2013-13363).—Stn 668, 21°40.5'S, 166°29.1'E, 40 m, August 1986: 1 M 5.2 mm (MNHN-IU-2013-9770).—Stn 671, 21°38.1'S, 166°25.5'E, 36–39 m, August 1986: 2 M 4.0– 5.4 mm (MNHN-IU-2013-13370).—Stn 675, 21°36.4'S, 166°23.9'E, 43 m, August 1986: 1 M 2.6 mm (MNHN-IU-2013-9772).—Stn 723, 21°21.6'S, 165°56.7'E, 45 m, August 1986: 3 M 4.0– 5.3 mm, 4 ov. F 3.8–4.3 mm (MNHN-IU-2013-13364).—Stn 726, 21°20.4'S, 165°55'E, 50-51 m, August 1986: 1 ov. F 4.2 mm (MNHN-IU-2013-9769).—Stn 737, 22°08.4'S, 166°59.1'E, 49–50 m, August 1986: 1 M 3.9 mm (MNHN-IU- 2013-9776).—Stn 739, 22°11.6'S, 167°01'E, 41–44 m, August 1986: 1 M 4.5 mm (MNHN-IU-2013-13328).—Stn 880, 20°29.9'S, 164°47.4'E, 30–52 m, 13 January 1987: 3 M 3.6–6.4 mm (MNHN-IU-2013-13330). Lagon, Stn DW1236, 21°18.13'S, 165°53.68'E, 45 m, 13 March 1993: 3 M 5.2–5.6 mm, 1 F 4.9 mm (MNHN-IU-2013-13374). Lagon North, Stn 504, 19°14.7'S, 163°30.5'E, 45 m, February 1985: 1 M 5.5 mm, 1 ov. F 3.1 mm (MNHN-IU- 2013-13356). Surprises Atoll, Stn 462, 18°20'S, 162°59'E, 40 m, 1 March 1985: 1 M 5.0 mm, 1 ov. F 3.7 mm (MNHN-IU-2013-13329). Lifou Island. LIFOU, Stn 1460, 20°52.4’S, 167°08.0’E, 40–60 m, 6 November 2000: 2 M 4.3–4.6 mm, 2 ov. F 3.2–3.8 mm (MNHN-IU-2013-13340).—Stn 1463, 20°55.05’S, 167°03.35’E, 20–30 m, 10 November 2000: 1 ov. F 3.0 mm (MNHN-IU-2013-13341).—Stn 1474, 20°54.8’S, 167°16.1’E, 0–3 m, 11 November 2000: 8 M 2.0– 4.6 mm, 1 ov. F 2.3 mm, 2 F 2.7–2.8 mm (MNHN-IU-2013-13339).—Stn 1459, 20°47.0’S, 167°03.0’E, 55–80 m, 5/ 13 November 2000: 4 M 2.0– 3.4 mm, 8 ov. F 2.3–4.2 mm (MNHN-IU-2013- 13331); 1 M 3.0 mm (MNHN-IU-2013-9906).—Stn 1464, 20°54.5’S, 167°05.9’E, 35–50 m, 14 November 2000: 1 M 3.4 mm (MNHN-IU-2013-13332); 2 M 3.2–3.4 mm (MNHN-IU-2013-13333).—Stn 1465, 20°47.7’S, 167°07.0’E, 35–45 m, 16 November 2000: 2 ov. F 3.0– 4.5 mm, 1 F 3.1 mm (MNHN-IU-2013-13337).—Stn 1466, 20°46.5’S, 167°06.2’E, 25–45 m, 17 November 2000: 4 M 1.7–1.8 mm, 2 ov. F 4.3 mm (MNHN-IU-2013- 13334).—Stn 1467, 20°46.6’S, 167°05.4’E, 90 m, 20 November 2000: 2 M 3.2–4.4 mm, 1 ov. F 4.3 mm (MNHN- IU-2013-13338).—Stn 1468, 20°46.5’S, 167°05.7’E, 30–80 m, 20 November 2000: 6 M 3.1–4.8 mm, 9 ov. F 2.9–5.5 mm (MNHN-IU-2013-13335).—Stn 1456, 20°49.3’S, 167°10.4’E, 25–30 m, 26 November 2000: 6 M 3.0– 4.7 mm, 3 ov. F 3.4–4.8 mm (MNHN-IU-2013-13336).

Etymology. The name Cymo , wave, refers to one of the Nereids of Greek mythology. The name is considered as a substantive in apposition.

Description. Carapace: Slightly longer than broad; ridges with dense short setae and some scattered long plumose setae; cervical groove nearly indistinct, laterally bifurcated; ridges on gastric and anterior branchial regions scale-like or in concentric arcs; epigastric region with 2 median spines, and 1 small parahepatic spine on each side. Mid-transverse ridge scale-like, preceded by shallow cervical groove, followed by 4 or 5 scale-like ridges, 1 of them uninterrupted; 1 postcervical spine on each side. Lateral margins slightly convex posteriorly, with 6 or 7 spines: 1 or 2 spines in front of, and 5 spines behind, anterior cervical groove; first anterolateral, welldeveloped, second minute or absent; additional well-developed spine ventral to between first lateral spine and anterior branch of cervical groove; 2 spines on anterior branchial margin, and 3 spines on posterior branchial margin. External limit of orbit ending in small spine; infraorbital margin with 1 spine. Rostrum triangular, 1.5–1.6 times as long as broad, 0.6 carapace length and breadth 0.4 that of carapace, nearly horizontal in lateral view; distance between distalmost lateral incisions 0.2 distance between proximalmost lateral incisions; dorsal surface with small setiferous ridges; lateral margin with 4 deeply incised sharp teeth.

Pterygostomian flap rugose, with sparse short setae, anterior margin with distal spine.

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

Abdomen: Somites 2–4 each with anterior transverse ridge only; somites 5 and 6 smooth, posteromedian margin of somite 6 nearly transverse. Males with G1 and G2.

Eyes: Ocular peduncles 1.5 times longer than broad, maximum corneal diameter 0.8 rostrum width.

Antennule: Article 1 with 2 well-developed spines, distodorsal larger; distomesial spine distinct but very small. Ultimate article with tuft of fine setae on distodorsal margin.

Antenna: Article 1 with ventral distomesial spine exceeding distal margin of article 2. Article 2 with 2 subequal distal spines, reaching midlength of article 3. Articles 3 and 4 unarmed.

Mxp3: Ischium with ending in blunt angle on flexor margin; extensor margin with small but distinct distal spine; crista dentata with 26–28 denticles. Merus equally long as ischium; flexor margin with 2 spines, proximal one located at midlength, distal one at terminal end, proximal clearly longer than distal; extensor margin with 1 or 2 small spines, proximal one located at midlength, distal one at terminal end. Carpus unarmed.

P1: 2.7–3.2 times carapace length, more so on fingers, and spinose, with sparse long plumose setae. Merus 1.2 times length of carapace, 1.8 times as long as carpus, with spines arranged roughly in rows, mesial and distal spines prominent. Carpus 0.8 length of palm, 1.9 times as long as broad; dorsal surface with spines arranged roughly in longitudinal rows; mesial margin with 3 well-developed spines, distal second largest. Palm 1.6–1.9 times longer than broad, lateral and mesial margins slightly divergent; spines arranged roughly in rows, dorsolateral row of spines continued on to whole lateral margin of fixed finger; dorsomesial row of spines continued along entire margin of movable finger. Fingers 0.9 length of palm, each finger with two rows of teeth distally spooned.

P2–4: Moderately slender, with numerous long plumose setae. P2 2.1 times carapace length. Meri successively shorter posteriorly (P3 merus 0.9 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.9 carapace length, 5.5 times as long as broad, 1.6 times longer than P2 propodus; P3 merus 4.4 times longer than broad, 1.4 times longer than P3 propodus; P4 merus 3.6 times as long as broad, 1.2 length of P4 propodus. Extensor margins with row of 9 or 10 proximally diminishing spines on P2–3, 2 or 3 on P4; lateral surface with 1 or 2 small spines on P4; flexor margin distally ending in strong spine followed proximally by 1–3 small spines and several eminences. Carpi with 4 or 5 spines on extensor margin on P2–4; lateral surface with 3 spines or granules sub-paralleling extensor margin on P2; flexor distal margin with small distal spine. Propodi 5.5–5.9 times as long as broad; extensor margin with 2 or 3 spines on proximal half; flexor margin with 4 or 5 slender movable spines. Dactyli subequal in length, distally ending in well-curved strong spine, 0.5–0.6 length of propodi; flexor margin with 5 or 6 proximally diminishing teeth.

Epipods on P1.

Coloration. Translucent light brown overall. Long setae on abdomen and pereopods whitish. P1 palm whitish with transverse dark brown stripe.

Remarks. Galathea cymo belongs to the group of species characterized by scale-like gastric ridges and the presence of at least one dorsal branchial spine. The closest relative is G. subsquamata Stimpson, 1858 from Japan (Oshima Strait), Mariana Islands, and Papua New Guinea (see Remarks of the latter species).

Distribution. Vanuatu, New Caledonia, Chesterfield Islands, 2–90 m, in dead Pocillopora spp.

Figures

FIGURE 30. Galathea cymo n. sp., holotype, male, 3.6 mm, Vanuatu (MNHN-IU- 2013 - 13327). A, carapace and abdomen, dorsal view; B, thoracic sternites 3 and 4; C, left part of cephalothorax, ventral view, showing antennular and antennal peduncles, and anterior part of pterygostomian flap; D, ischium, merus and carpus of right Mxp 3, lateral view; E, right P 1, dorsal view; F, right P 2, lateral view; G, right P 3, lateral view; H, right P 4, lateral view. Scale: A, E – H = 1 mm; B – D = 0.5 mm.

FIGURE 116. Dorsal view. A, Galathea boucheti n. sp., Madagascar, holotype, male 4.0 mm (MNHN-IU- 2013 - 8110). B, Galathea caesariata n. sp., Vanuatu, holotype, male 5.0 mm (MNHN-IU- 2013 - 15938). C, Galathea celiae n. sp., Red Sea, male 2.8 mm (UF 32860). D, Galathea consobrina De Man, 1902, Vanuatu, female 3.2 mm (MNHN-IU- 2013 - 8386). E, Galathea cymo n. sp., Vanuatu, ovigerous female 4.0 mm (MNHN-IU- 2013 - 13343). F, Galathea erythrina n. sp., Red Sea, holotype, female 1.3 mm (UF 36824). G, Galathea eulimene n. sp., Red Sea, Saudi Arabia, male 3.1 mm (UF 35961). H, Galathea galene n. sp., ovigerous female 5.4 mm (MNHN-IU- 2013 - 9878). I, Galathea gladiola n. sp., Vanuatu, holotype, female 4.5 mm (MNHN-IU- 2013 - 8436).