Gamboa henrieti, Esquete & Cunha, 2018

Esquete, Patricia & Cunha, Marina R., 2018, Additions to the Tanaidomorpha (Crustacea: Tanaidacea) from mud volcanoes and coral mounds of the Gulf of Cadiz and Horseshoe Continental Rise, Zootaxa 4377 (4), pp. 517-541 : 535-539

Gamboa henrieti sp. nov.

( Figs 11–13 )

Material examined. Holotype— ♀ with marsupium ( MNCN 20.04/11448), Cruise 64PE268, station 64PE268_24, NIOZ boxcore, 0 6.05.2007, GoC, carbonate and coral mounds, Mound B, 35°17.732'N, 06°43.886'W, 495 m, silty clay with carbonate debris.

Paratypes— two neuters ( DBUA0002223.01 ), same data as holotype. All coll. CFR.

Further material— Gulf of Cadiz—Carbonate and coral mounds. Mound B: station 64PE268_13B, NIOZ boxcore, 0 3.05.2007, 35°18.010' N, 06°44.493' W, 493 m, one ♀ with marsupium, dissected; two neuters ( DBUA0002223.02 ), coll. CFR.

Etymology. In honour of Jean-Pierre Henriet (1945-2017), distinguished Belgian marine geologist and great enthusiast of cold water coral and carbonate mound research in the Gulf of Cadiz.

Diagnosis. Body 7.5 times as long as broad. Cephalothorax as long as broad, rostrum rounded, eyelobes present, with vestigial ommatidia. Pereonites 1 and 6 broader than long, pereonites 2–5 about as long as broad. Antennule longer than cephalothorax. Maxilliped endites with three setae. Cheliped carpus and propodus with two ventral setae each. Female chela fixed finger longer than palm. Ischia of all pereopods with setae, unguis not bifurcate.

Description of female with marsupium DBUA0002223.02. Body ( Fig. 11A, B ) 7.5 times as long as broad, length 1.2 mm. Cephalothorax as long as broad, rostrum rounded, eyelobes present, with vestigial ommatidia. Pereonite 1 2.3 times as broad as long; pereonites 2–5 about as long as broad; pereonite 6 0.8 times as long as broad. Pleon narrower than pereon, pleonites alike, demarcated by a faint line. Pleotelson as long as four pleonites.

Antennule ( Fig. 11C ) longer than cephalothorax. Article 1 3.3 times as long as broad, inner margin with one simple and one penicillate medial setae, and one simple and one penicillate distal setae. Outer margin with one distal seta. Article 2 0.2 times as long as article 1, 1.3 times as long as broad, with one inner distal seta. Article 3 2.1 times as long as article 2, 5.7 times as long as broad, with four distal setae and one aesthetasc.

Antenna ( Fig. 11D ) article 1 as long as broad, naked. Article 2 2.4 times as long as broad, with one dorsodistal seta. Article 3 0.7 times as long as article 2, 1.1 times as long as broad, with one dorsodistal seta. Article 4 3.5 times as long as article 3, 5.2 times as long as broad, with five distal setae. Article 5 0.3 times as long as article 4, 2.6 times as long as broad, with two distal setae. Article 6 minute, with four distal setae.

Mouthparts. Labrum ( Fig. 12A ) rhomboidal, clypeus distinct, with setae. Left mandible ( Fig. 12B ) pars incisiva with four cusps, lacinia mobilis crenulated; pars molaris armed with teeth. Right mandible ( Fig. 12C ) pars incisiva crenulated, with two terminal cusps, without lacinia mobilis, pars molaris as in left mandible. Labium not recovered. Maxillule ( Fig. 12D ) endite bent almost at a right-angle, with seven terminal spines. Maxilla ( Fig. 12E ) rectangular.

Maxilliped endite ( Fig. 12G ) with three setae; palp ( Fig. 12F ) article 1 with one inner seta; article 2 with one outer seta and three inner serrulate setae; article 3 with three inner pinnate setae; article 4 with three distal and one subdistal pinnate setae.

Cheliped ( Fig. 13A, C ) attached via elongated sclerite. Basis 1.7 times as long as broad, naked. Merus with one seta. Carpus 2.2 times as long as broad, with two ventral setae. Propodus twice as long as broad, 1.2 times as long as carpus, with two ventral setae, three setae near cutting edge, and inner row of three setae near insertion with dactylus. Dactylus with one inner proximal seta; unguis with one outer seta.

Pereopod 1 ( Fig. 13D ) coxa with seta. Basis slightly curved, 4.4 times as long as broad, naked. Ischium with one ventral seta. Merus 0.3 times as long as broad, naked. Carpus as long as merus, with one ventrodistal seta. Propodus 2.2 times as long as carpus, with one subdistal ventral seta. Dactylus and unguis fused, together about as long as propodus.

Pereopods 2–3 ( Fig. 13E ) coxa with one seta. Basis 4.2 times as long as broad, with one mediodorsal seta. Ischium with two ventral setae. Merus 0.3 times as long as basis, 1.1 times as long as broad, with two ventrodistal spines. Carpus 1.2 times as long as merus, 1.5 times as long as broad, with one dorsodistal and two unequal ventrodistal spines. Propodus 1.5 times as long as carpus, 2.5 times as long as broad, with ventral subdistal spine. Dactylus and unguis fused to claw.

Pereopods 4–5 ( Fig. 13F ) basis 3.1 times as long as broad, with one medioventral penicillate seta. Ischium with two ventral setae. Merus 1.2 times as long as broad, with two ventrodistal spines. Carpus 1.9 times as long as broad, with three ventrodistal spines and one dorsodistal seta. Propodus 1.3 times as long as carpus, 3.0 times as long as broad, ventrodistal margin with two spines and one seta, dorsodistal corner with one seta.

Pereopod 6 ( Fig. 13G ) basis 2.7 times as long as broad, naked. Ischium with two ventral setae. Merus 0.3 times as long as basis, 1.1 times as long as broad, with two ventrodistal spines. Carpus 1.1 times as long as merus, 1.2 times as long as broad, with three ventrodistal spines and one dorsodistal seta. Propodus 1.3 times as long as carpus, 2.7 times as long as broad, with two ventrodistal spines and one dorsodistal setae.

Pleopods absent.

Uropod ( Fig. 13H ) protopod about as long as broad, naked. Exopod first segment 2.5 times as long as broad, with one distal seta; second segment 1.3 times as long as first, with two distal setae. Endopod 1.6 times as long as exopod; first segment 3.2 times as long as broad; second segment as long as first, with five distal setae.

Remarks. This species differs from the diagnosis of Gamboa given by Bamber (2012) because of the presence of a first pereonite shorter than pereonites 2 and 3, the antennule longer than cephalothorax, the cheliped with two setae on carpus and propodus (instead of one), the fixed finger of chela not shorter than palm, the bases and ischia of pereonites not naked, and the unguis of pereonites 4–6 not bifurcated. Nevertheless, the absence of pleonites is a character unique of Gamboa amongst the Nototanaidae , as it is the combination of the following characters: eye lobes fused to the carapace, maxilliped basis without setae, endites with setae but no distal tubercles, coxae with setae and without apophyses, pereopods 4–6 merus, carpus and propodus with spines and without prickly tubercles, and uropods with endopod longer than exopod. Consequently, the species described here is included in Gamboa and the diagnosis emended above in order to accommodate both Gamboa darwini Bamber, 2012 and Gamboa henrieti sp. nov.

In addition to the characters mentioned above that were initially included in the generic diagnosis, the type species Gamboa darwini differs from Gamboa henrieti in having a cephalothorax longer than broad, maxilliped endite with two setae, pereopod 1 propodus with two dorsal setae, pereopods 2 and 3 merus and carpus with one ventral seta only and propodus with one dorsal seta.

Distribution and ecology. This species was found exclusively in fine sediments with coarse materials from a fossil cold-water coral and carbonate mound (Mound B) at the El Arraiche field (Moroccan margin).

Figures

FIGURE 11. Gamboa henrieti sp. nov. FeMALe SPecIMeN DBUA0002223.02A: A, hAbITUS (DORSAL VIeW); B, hAbITUS (LATeRAL VIeW); C, ANTeNNULe;D, ANTeNNA.

FIGURE12. Gamboa henrietisp. nov. FeMALeSPecIMeN DBUA0002223.02B:A, LAbRUM;B, LeFTMANDIbLe;C, RIGhT MANDIbLe; D, MAXILLULe;E, MAXILLA;F, MAXILLIPeD PALP;G, MAXILLIPeD eNDITe.

FIGURE 13. Gamboa henrieti sp. nov. FeMALe SPecIMeN DBUA0002223.02B: A, cheLIPeD cARPUS AND cheLA, OUTeR VIeW; B, cheLIPeD cARPUS AND cheLA, INNeR VIeW; C, cheLIPeD bASIS, MeRUS AND ScLeRITe; D, PeReOPOD 1; E, PeReOPOD 2; E, PeReOPOD 3; F, PeReOPOD 4; G, PeReOPOD 6; H, UROPOD.