Praedatrypaea inhambane, Poore, 2023

Poore, Gary C. B., 2023, New records, one new genus and 21 new species of Callianassidae (Crustacea, Axiidea) from the Indo-West Pacific, Memoirs of Museum Victoria 82, pp. 167-255 : 204-205

Praedatrypaea inhambane sp. nov.

http://zoobank.org/urn:lsid:zoobank.org:act:DFE9A6D4-4E55-

4070-9A5C-8573163E2951

Figure 26

Material examined. Holotype. Mozambique, Mozambique Channel , Inhambane transect, 24° 15.70' S, 35° 42.20' E, 605–612 m

(MAINBAZA stn CC3165), MNHN IU-2008-10312# (female, 4.3 mm, without pereopods).

Diagnosis. Antennular peduncle reaching just beyond distal margin of antennal peduncle article 4. Maxilliped 3 ischium about 1.6 times as long as wide; merus subsquare, about 1.2 times as wide distally as long, with small tooth on transverse distal margin. Chelipeds unknown. Uropod endopod oval, 1.5 times as long as wide; anterior margin slightly convex, with 5 distal stout setae; distal margin convex; dorsal face without proximal spiniform setae. Uropod exopod widest subdistally, 1.3 times as long as wide; anterior margin almost straight, with few setae. Telson 1.4 times as long as wide, widest at strong lateral lobes at one sixth length; posterior margin convex, with median spine.

Description of female holotype. Rostrum acute, narrow in dorsal view, situated below level of dorsal carapace, 0.75 length of eyestalks. Carapace orbital margin almost transverse; anterolateral lobes triangular; subanterolateral margin steeply oblique. Pleomere 6 damaged.

Eyestalk 1.55 times as long as wide, with oblique dorsal face diverging from rostrum, anterolateral margin convex, thin, flange-like, not reaching distal margin of antennular peduncle article 1. Cornea with small separate pigmented ommatidia, sitting in midpart of eyestalk.

Antennular peduncle reaching one third way along antennal peduncle article 5; article 1 visible in dorsal view; article 3 shorter than articles 1 and 2 combined; articles 2 and 3 with longitudinal ventral row of long setae. Antennal peduncle article 5 0.6 length of article 4; scaphocerite triangular in dorsal view.

Maxilliped 3 ischium subrectangular, about 1.6 times as long as wide, crista dentata flange-like, of row of about 20 uneven contiguous teeth (ischium triangular in cross-section); merus subsquare, 0.7 length of ischium measured along outer margin, about 1.2 times as wide distally as long, with small tooth on transverse distal margin; carpus about as long as merus outer margin; propodus tapering, 1.9 times as long as greatest width; dactylus 0.8 length of propodus, elongate-oval, with dense row of short setae along flexor (lower) margin.

Chelipeds, pereopods unknown.

Uropod endopod and exopod not overreaching posterior margin of telson. Endopod oval, 1.5 times as long as wide; anterior margin slightly convex; anterodistal margin with 5 subdistal spiniform setae; dorsal face unarmed. Exopod widest subdistally, 1.3 times as long as wide; anterior margin almost straight, with few setae; posterior margin with about 10 falcate setae indistinguishably merged with densely setose distal margin; dorsal plate differentiated from distal margin, comprising 2 or 3 rows of short and medium stiff setae merging anteriorly with similar setae on distal margin; dorsal face without spiniform seta.

Telson 1.4 times as long as wide, widest at strong lateral lobes at one sixth length; narrowing posteriorly to rounded corner leading to posterior margin; posterolateral margin convex, setose, with medial spine.

Etymology. From Inhambane, Mozambique, city near the type locality (noun in apposition).

Distribution. Western Indian Ocean; 605–612 m (known only from type locality).

Remarks. A single incomplete specimen was referable to this genus on the basis of the maxilliped 3, telson, rostrum and antennae. It was taken close to the type locality of P. jangamo sp. nov. but at a greater depth. The specimen was much smaller than the type of P. jangamo and differed in the position of the tooth on the merus of maxilliped 3 and in shapes of the telson and uropod. The specimen differs from all other species in the mesial position of the tooth on the maxilliped 3 merus and the absence of facial setae on the uropodal rami.

Figures

Figure 26. Praedatrypaea inhambane. Mozambique, MNHN IU-2008-10312, female, 4.3 mm: a, telson, right uropod; b, c, anterior carapace, antennular, antennal peduncles, eyestalks (lateral, dorsal views); d, maxilliped 3 (outer view, merus flattened); e, maxilliped 3 (inner view, merus flexed). Scale bars = 1 mm.