Typhlotanais priscilae Segadilha & Serejo 2022, sp. nov.
Creators: name: Segadilha, Juliana L.
name: Serejo, Cristiana S.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Tanaidacea
Typhlotanaidae
Typhlotanais
Typhlotanais priscilae

description: Typhlotanais priscilae sp. nov.
urn:lsid:zoobank.org:act: 373A54F6-39DF-4AE4-BB1A-5C18E8D82EBD
Figs. 14–16, 21
Diagnosis
Body 5.0 × L:W; cephalothorax rounded; antenna article-3 with long seta reaching half-length of article-4; pereopod-1 carpus with two distal long setae (one dorsal and one ventral); pereopods 2–3 ischium with stout seta as long as merus distal margin; propodus with ventrodistal seta; dactylus with seta twice as long as unguis; pereopods 4–6 propodus seta longer than dactylus and unguis combined; uropod stout, 0.9× as long as pleotelson; exopod one-articled, 0.9× as long as endopod; endopod onearticled, 3.0× L:W.
Etymology
Named in honour of MSc. Priscila Soares do Nascimento (Museu Nacional/UFRJ) in recognition of her friendship, collaboration, and great enthusiasm during many years at the Carcinology Lab of Museu Nacional/UFRJ.
Material examined
Holotype
BRAZIL – Espírito Santo State • ♀ ovigerous, length 1.2 mm; Espírito Santo Basin; stn AMB 8 E7 R 1; 19.7850° S, 39.0533° W; depth 1258 m; 28 Jan. 2012; MZUSP 38972.
Paratypes
BRAZIL – Rio de Janeiro State • 1 neuter (dissected), length 1.2 mm; Campos Basin, stn HAB 3 C8 R1; 23.0257° S, 40.7565° W; depth 975 m; 10 May 2008; MZUSP 38017. – Espírito Santo State • 1 neuter; Espírito Santo Basin, stn AMB 6 CAMWN 6 R1; 19.8914° S, 39.5487° W; depth 1023 m; 13 Jan. 2012; MZUSP 38962.
Additional material (lost in the fire)
BRAZIL – Rio de Janeiro State • 2 neuters; Campos Basin, HAB 3 C8 R3; 23.0257° S, 40.7565° W; depth 975 m; 10 May 2008; MZUSP 22907 • 1 neuter; Campos Basin, stn HAB 3 B8 R 2; 23.2298° S, 40.9323° W; depth 986.4 m; 8 May 2008; MZUSP 32867 • 1 neuter; Campos Basin, stn HAB 3 B8; 23.2298° S, 40.9323° W; depth 986.4 m; 8 May 2008; MZUSP 34436.
Description
Paratype (MZUSP 38009 dissected)
MEASUREMENTS. Length 1.2 mm. Body (Fig. 14A–B) slender, 5.1 × L:W. Cephalothorax rounded 1.1× L:W, 1.1× as long as pereonite-1, naked; eyes absent. PEREONITES 1–6. All pereonites rectangular, longer than wide, with lateral margins gently convex; pereonite-1 shortest, 0.3 × L:W, with minute seta on proximal margin; pereonite-2 0.5× L:W; pereonite-3 0.4 × L:W; pereonite-4 0.6× L:W, with two minute setae on lateral margin; pereonite-5 0.7× L:W, with minute seta on lateral margin; pereonite-6 0.5× L:W.
PLEON (Fig. 14A–B) 0.3× TBL, with five subequal pleonites, together longer than carapace and pereonite-1 combined. Pleotelson trapezoidal 0.6× L:W, with a pair of terminal spines and three pairs of setae distally.
ANTENNULE (Fig. 14C). As long as cephalothorax, with three articles; article-1 0.6× TL, 2.3× L:W, with rod and seven penicillate middle setae, and with rod and four penicillate distal setae; article-2 0.8× L:W, 0.3 × as long as article-1, with two rod and penicillate distal setae; article-3 3.7× L:W, 2.3 × as long as article-2, with six rod and penicillate terminal setae.
ANTENNA (Fig. 14D) of six articles, article-1 lost during dissection; article-2 broken during dissection, with rod seta; article-3 0.9× L:W, with long penicillate seta (reaching half length of article-4); article-4 3.8× L:W, 3.8× as long as article-3, with strong microtrichia on outer margin, two stout rod and two penicillate distal setae; article-5 2.9× L:W, 0.5 × as long as article-4, with distal rod seta; article-6 minute with five rod terminal setae.
LABRUM (Fig. 15A). Rounded, hood-shaped, distally covered by minute setae. Mandible (Fig. 15B–C) molar broad well-developed with many prominent nodules. Left mandible (Fig. 15B) incisor simple, lacinia mobilis well developed, with four lobes; right mandible (Fig. 15C) incisor distally truncated gently undulated, without lacinia mobilis. Labium (Fig. 15D) with distolateral corner finely setose; outer lobe membranous. Maxillule (Fig. 15E) endite with eight terminal spines (one short); palp with two distal stout setae. Maxilla (Fig. 15F) triangular. Epignath (Fig. 15G) elongate, linguiform, naked. Maxilliped (Fig. 15H) sparsely setose; basis with simple as long as distal margin of endites; endites with two large gustatory cusps and seta on distal edge and microtrichia on outer corner; palp with four articles; article-1 triangular, naked; article-2 with three inner setae (one simple, one rod and one serrated) and seta on outer margin; article-3 with three serrated and one simple inner setae; article-4 with five serrated inner setae and subdistal outer seta.
CHELIPED (Fig. 15I). Slender, basis elongate, distally rounded, 2.6× L:W, with dorsodistal seta; merus subtriangular, with ventral seta; carpus 2.1× L:W, with two ventral setae; propodus 1.1× as long as carpus, 2.6× L:W, with two setae near dactylus insertion (one on inner and one on outer side); fixed finger with two rod ventral setae; cutting edge almost simple, with small subdistal protrusion and three rod setae; dactylus as long as fixed finger.
PEREOPOD-1 (Fig. 16A). Walking type, with strong microtrichia; slender, longer than others; coxa with seta; basis elongate 4.6× L:W, naked; ischium with ventral stout seta; merus 1.6 × L:W, with dorsodistal rod and ventrodistal simple setae; carpus 1.7 × L:W, slightly longer than merus, with two dorsodistal (one long and one short) and two ventrodistal setae (one long and one short); propodus 2.6× L:W, 1.1× as long as carpus, with three stout dorsodistal and one ventrodistal setae; dactylus 1.2 × as long as unguis, with seta as long as unguis; dactylus and unguis together 0.8× as long as propodus.
PEREOPOD-2 (Fig. 16B). Walking type, with strong microtrichia; coxa with seta; basis 3.6 × L:W, naked; ischium with ventral stout seta (as long as merus distal margin); merus about as long as wide, with dorsodistal and ventrodistal setae; carpus 0.8× L:W, with dorsodistal seta and ventrodistal robust spine; propodus 1.9× L:W, 0.7× as long as merus and carpus combined, with two dorsodistal (one slightly serrated and one rod) and ventrodistal simple setae; dactylus 1.2 × as long as unguis, with long seta twice as long as unguis (broken during dissection); dactylus and unguis together 0.9 × as long as propodus.
PEREOPOD-3 (Fig. 16C). Similar to pereopod-2, except basis 2.7× L:W, with ventral rod seta; merus with one ventrodistal seta; carpus 1.1 × L:W; propodus 2.4 × L:W.
PEREOPOD-4 (Fig. 16D). Clinging type, with strong microtrichia; coxa absent; basis robust 1.3× L:W, with two long penicillate ventral setae; ischium with seta; merus triangular about 2.2× L:W, with two ventrodistal spines (only one illustrated); carpus 1.5× L:W, with dorsodistal spine and prickly tubercles about as long as half carpus; propodus 3.1 × L:W, with slightly serrated dorsodistal seta longer than unguis and two ventrodistal spines (only one illustrated); dactylus 3.2 × as long as unguis, both combined 0.9 × as long as propodus.
PEREOPOD-5 (Fig. 16E) similar to pereopod-4, except basis 1.7× L:W, naked; propodus with penicillate middorsal seta.
PEREOPOD-6 (Fig. 16F). Similar to pereopod-4, except basis twice L:W, with penicillate dorsal seta; propodus with three slightly serrated dorsodistal setae (one longer than and two as long as unguis).
PLEOPOD (Fig. 16G). All pleopods similar; basal article naked; exopod with seven plumose setae on outer margin and with plumose seta on inner margin; endopod with twelve plumose setae on outer margin; gap between proximal seta and others in both rami.
UROPOD (Fig. 16H). Stout, 0.9× as long as pleotelson; basis 0.8× L:W, naked; exopod one-articled, 4.4× L:W, 0.9 × as long as endopod, with simple medial seta, one stout and one minute setae distally; endopod one-articled; 3.3 × L:W, with subdistal stout seta, two rod, two simple and two penicillate setae distally.
Distribution
Brazil: Campos Basin, Rio de Janeiro and Espírito Santo Basin, Espírito Santo. Occurring on the middle slope, depth range from 975 to 1258 m (Fig. 21).
Remarks
Typhlotanais priscilae sp. nov. is part of the ‘ spinicauda ’ group by the presence of two strong spines on distal margin of pleotelson (Table 4). The new species can be distinguished from both T. spinicauda and T. squamiger by its (1) body stout, 5.0 × L:W (T. spinicauda 7.5× L:W and T. squamiger 8.3 × L:W); (2) antenna article-3 with long seta reaching half length of article-4; (3) pereopod-1 carpus with two long setae; (4) pereopods 1–3 ischium with long seta; (5) pereopods 2–3 propodus with ventrodistal seta (instead of spine); (6) pereopods 2–3 dactylus with seta twice as long as unguis; (7) pereopods 4–6 propodus seta longer than unguis; (8) uropod stout, 0.9× as long as pleotelson; (9) uropod exopod onearticled, 0.9× as long as endopod; (10) uropod endopod one-articled, 3.0× L:W.
“ trispinosus ” group
Species included
Typhlotanais spatulasetosus Larsen, 2012; T. tenuicornis Sars, 1882; T. trispinosus Hansen, 1913; T. spinibasis sp. nov.
description: Published as part of Segadilha, Juliana L. & Serejo, Cristiana S., 2022, New insights gained from museum collections: new deep-sea species of Typhlotanais (Tanaidacea, Typhlotanaidae) from Brazil, pp. 1-54 in European Journal of Taxonomy 820 on pages 35-41, DOI: 10.5852/ejt.2022.820.1791, http://zenodo.org/record/6574383