Sinelobus bathykolpos, Bamber, 2014

Bamber, Roger N, 2014, Two new species of Sinelobus Sieg, 1980 (Crustacea: Tanaidacea: Tanaididae), and a correction to the higher taxonomic nomenclature, Journal of Natural History 48 (33 - 34), pp. 2049-2068 : 2059-2065

publication ID	https://doi.org/ 10.1080/00222933.2014.897767
DOI	https://doi.org/10.5281/zenodo.5195953
persistent identifier	https://treatment.plazi.org/id/03E687FD-4E7E-FFB1-FDCE-E81C0A9A92BA
treatment provided by	Felipe
scientific name	Sinelobus bathykolpos
status	sp. nov.

Treatment

Sinelobus bathykolpos View in CoL sp. nov.

( Figures 5–8 View Figure 5 View Figure 6 View Figure 7 View Figure 8 )

Sinelobus stanfordi Bird & Bamber 2000 View in CoL , 67: fig. 1, non- Tanais stanfordi Richardson, 1901 View in CoL .

Type material

Holotype. 1 male, ( BMNH 1999.1898 ), littoral mud amongst mangroves, Sheung Pak Nei , Deep Bay, western New Territories, Hong Kong; salinity <20‰.

Paratypes. One brooding female with 16 eggs ( BMNH 1999.1899 : microslide mount), two juveniles ( BMNH 1999.1900 - 1901 ), same data as holotype .

Other material examined: 15 females (four brooding), four males, seven juveniles; same sample details as primary types (material lost).

Diagnosis

Antennal peduncle article 2 without distal tuft of setae; antennal peduncle articles 2 and 3 with dorsal flange; lacinia mobilis of right mandible narrower distally, with three denticulations; lacinia mobilis of left mandible wider than long; maxilliped palp distal article 2.5 times as long as wide; six distal spines on maxillular endite, four distal setae on maxilliped endite; no proximal seta-bearing tubercle on female chela fixed finger; carpi of pereopods 2 and 4 with four distal spines; pereopod 6 with ventrodistal row of five leaf-like spines on propodus; pleopod 1 basis outer margin with five setae; uropod basis in female as long as first uropod segment. Male carapace 1.2 times as long as basal width; one proximal ventral apophysis on male cheliped carpus, one proximal ventral apophyses on male cheliped merus.

Description of brooding female

Body ( Figure 5B View Figure 5 ) 4.4 times as long as wide, dorsally with black mottling on cephalon and pereonites (in preserved material); length of paratype 1.6 mm. Cephalothorax narrower towards anterior with rounded mid-lateral indentation, 1.1 times as wide as long, with slight rounded frons but no rostrum, eyes present, pigmented. Cephalothorax just shorter than pereonites 1–3 together. Pereonites rounded laterally, pereonites 1–3 with one small anterolateral seta on each side, pereonites 4–6 with two lateral setae on each side; pereonite 1 shortest, 0.3 times as long as cephalothorax; pereonites 2 and 3 subequal, 1.3 times as long as pereonite 1; pereonites 4 and 5 subequal, longest, 1.9 times as long as pereonite 1, pereonite 6 just shorter, 0.9 times as long as pereonite 5 (all pereonites, respectively, 3.8, 2.9, 2.7, 1.8, 1.8 and 1.9 times as wide as long). Pleonites 1–3 bearing pleopods and with transverse latero-dorsal rows of setae hardly extending onto dorsal surface, less well developed on pleonite 3; pleonite 4 shorter and narrower, with two lateral setae. Pleotelson semicircular, 1.9 times as wide as long, with single mid-lateral seta, shorter subdistal dorsal seta and paired distal setae on each side.

Antennule ( Figure 6A View Figure 6 ) with proximal peduncle article 2.7 times as long as wide with mid-outer tuft of penicillate setae, inner distal seta and outer distal tuft of simple setae; second article one-third as long as first with inner distal seta and outer distal tuft of one penicillate and three simple setae; third article 1.4 times as long as second, with two distal setae; distal segment very small, with six distal setae and one aesthetasc.

Antenna ( Figure 6B View Figure 6 ) with first article compact, naked, half length of second; second article with distinct dorsal flange-like expansion and ventrodistal seta; third article half length of second, with dorsal flange-like expansion, naked; fourth article just longer than second article, naked; fifth article as long as fourth, with three distal setae; distal segment very small with seven distal setae.

Labrum ( Figure 6C View Figure 6 ) squared, distally setose. Left mandible ( Figure 6D View Figure 6 ) with wide, robust, distally denticulate lacinia mobilis and adjacent seta; right mandible ( Figure 6E View Figure 6 ) with narrower, distally crenulate lacinia mobilis; pars molaris of each mandible robust, rugose. Labium ( Figure 6G View Figure 6 ) wide, all lobes finely setose distally. Maxillule ( Figure 6F View Figure 6 ) with seven distal spines, finely setose outer margin. Maxilla not recovered. Maxilliped ( Figure 6H View Figure 6 ) coxa with single inner seta; basis with single seta reaching to half length of second palp article; first palp article naked, second palp article with outer seta and four simple inner setae; third article with eight simple inner setae in two rows; fourth article with five distal and one outer subdistal simple setae. Maxilliped endites ( Figure 6I View Figure 6 ) with two simple and two longer coarsely-plumose setae. Epignath ( Figure 6J View Figure 6 ) typical of genus, elongate with distal spine and finely setose margins.

Cheliped ( Figure 7A View Figure 7 ) comparatively stout, basis 1.4 times as long as wide with ventrodistal seta, sidepiece with outer seta; merus ventrally with single seta and slight proximal rounded apophysis; carpus 1.6 times as long as wide, dorsally with two distal and one proximal setae, mid-ventrally with two setae; propodus as wide as long, with single ventral seta, one inner distal seta at dactylus attachment; fixed finger with outer distal tubercle bearing four setae, two inner distal setae, cutting edge distally expanded into rounded lamella; dactylus naked.

Pereopod 1 ( Figure 7B View Figure 7 ) coxa with seta but no apophysis; ischiobasis slender, 3.9 times as long as wide, with dorsal and ventral simple setae in proximal half; merus 0.2 times length of ischiobasis; carpus 1.9 times as long as merus, with single dorsodistal and ventrodistal setae; propodus 1.5 times as long as carpus, with one mid-dorsal, one dorsodistal and one ventrodistal simple setae; dactylus 1.4 times as long as unguis, both together 0.8 times as long as propodus. Pereopod 2 ( Figure 7C View Figure 7 ) coxa with seta; ischiobasis three times as long as wide with ventrodistal seta; merus one-third length of ischiobasis with ventrodistal seta and short tooth-like spine; carpus compact, 0.9 times as long as merus, with dorsodistal seta, three anterodistal and one posterodistal short toothlike spines, sparse ventral microtrichia; propodus 1.4 times as long as carpus, with single dorsodistal and ventrodistal setae; dactylus plus claw as long as carpus. Pereopod 3 ( Figure 7D View Figure 7 ) similar to pereopod 2 but dactylus plus claw as long as propodus.

Pereopod 4 ( Figure 7E View Figure 7 ) ischiobasis 2.7 times as long as wide, with ventral penicillate seta and one ventrodistal seta; merus one-third as long as ischiobasis, with paired subdistal ventral short spines; carpus as long as merus, with crown of three anterodistal and one posterodistal short tooth-like spines, and dorsodistal seta; propodus 1.2 times as long as carpus, with three shorter distal setae and two longer dorsodistal setae; dactylus and unguis fused into a claw, curved, with lateral comb of nine spinules. Pereopod 5 ( Figure 7F View Figure 7 ) similar to pereopod 4, but ischiobasis with two ventral subdistal simple setae. Pereopod 6 ( Figure 7G View Figure 7 ) similar to pereopod 5, but without subdistal setae on ischiobasis, and propodus with distal row of five leaf-like spines.

Pleopod ( Figure 7H View Figure 7 ) basis with one plumose seta on inner margin and five (pleopods 1 and 2) or four (pleopod 3) outer plumose setae; exopod with 24 plumose setae along outer edge; endopod with one inner and 13 outer plumose setae, distally with shorter, stout, articulate seta.

Uropod ( Figure 8A View Figure 8 ) uniramous, of three segments plus basis, second segment 1.6 times as long as first, other segments and basis subequal in length.

Description of male

Body ( Figure 5A View Figure 5 ) slightly longer than, but of similar proportion and pigmentation to that of female, but cephalothorax anteriorly narrowed, 1.2 times as long as wide; holotype body-length 1.75 mm. Antennule ( Figure 8B View Figure 8 ) more elongate than that of female, proximal peduncle article five times as long as wide; distal segment with seven simple setae and one aesthetasc. Antenna appearing more slender than that of female, not dissected.

Cheliped ( Figure 8C View Figure 8 ) more robust than that of female, basis 1.4 times as long as wide with one ventrodistal seta; merus with mid-ventral seta and one rounded ventroproximal apophysis; carpus 1.1 times as long as wide with two mid-ventral setae and one ventroproximal rounded apophysis; propodus massive, 0.8 times as long as wide; cutting edge of dactylus with proximal lamella.

Etymology

From the Greek bathy – deep, and kolpos – bay or inlet, the type locality being on the shore of Deep Bay , Hong Kong .

Remarks

Sinelobus bathykolpos sp. nov. shares only with S. pinkenba the dorsal flange on antennal peduncle articles 2 and 3, and the presence of only one proximal ventral apophysis on the carpus of the male cheliped, as well as having a ventral apophysis on the merus of that cheliped. It has only four distal spines on the carpi of pereopods 2–6, all other species having five such spines. The lacinia mobilis of the right mandible in the present species is unique in the genus in being distally narrower. With an adult female body-length of 1.6 mm, it is the smallest Sinelobus species yet described.

Type locality: Deep Bay, western New Territories, Hong Kong.