Tetraxanthus rathbunae Chace 1939
Creators: name: Bochini, Gabriel L.
name: Santos, Rafael C.
name: Zara, Fernando J.
name: Costa, Rogério C.
name: Mantelatto, Fernando L.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Pseudorhombilidae
Tetraxanthus
Tetraxanthus rathbunae

description: Tetraxanthus rathbunae Chace, 1939
(Fig. 1)
Measurements of larvae: CL, 0.45 ± 0.03 mm; n = 10.
Carapace (Fig. 1a): globose; dorsal spine long, lightly curved backward, without setae; rostral spines shorter than antennal protopod; lateral spines short; anterodorsal and posterodorsal sensory dorsal organs (SDO); 1 pair of posterodorsal, distally simple, setae; sessile eyes.
Antennule (Fig. 1c): not articled, with 2 long and 2 shorter and thinner terminal aesthetascs, 1 simple seta; accessory flagellum absent.
Antenna (Fig. 1d, e): uniramous; long, well-developed multispinulate protopod; endopod spine present; not articled exopod, with 5 unequal terminal simple setae and 1 lateral simple seta on outer side.
Mandible (Fig. 1f): with medial dentate molar process and enlarged lateral incisor process; palp absent.
Maxillule (Fig. 1g): coxal endite with 7 (3 subterminal + 4 terminal) plumodenticulate setae; basial endite with 5 plumodenticulate setae; 2-articled endopod, with 1 plumodenticulate seta on proximal articled and 6 (2 subterminal + 4 terminal) plumodenticulate setae.
Maxilla (Fig. 1h): coxal endite bilobed, with 4 (3 plumose + 1 plumodenticulate) + 4 (2 plumose + 2 plumodenticulate) setae; bilobed basal endite, with 5 + 4 plumodenticulate setae; bilobed endopod, with 3 plumodenticulate + 5 (4 plumodenticulate + 1 sparsely plumose) setae; scaphognathite with 4 marginal plumose setae and 1 stout posterior process.
First maxilliped (Fig. 1i): coxa with 1 simple seta; basis with 10 sparsely plumose setae arranged in 2+2+3+3; 5-articled endopod, with 3 (1 simple seta + 2 sparsely plumose) setae, 2 (1 simple + 1 sparsely plumose) setae, 1 sparsely plumose seta, 2 sparsely plumose setae, and 5 (1 simple + 4 terminal plumodenticulate) setae; 2-articled exopod, with 4 terminal natatory plumose setae.
Second maxilliped (Fig. 1j): coxa without setae; basis with 4 medial sparsely plumose setae arranged in 1+1+1+1; 3-articled endopod, with 1 simple seta, 1 plumodenticulate seta, and 6 (2 long and 1 short sparsely plumose + 2 simple + 1 plumodenticulate) setae; not articled exopod with 4 terminal natatory plumose setae.
Third maxilliped: absent.
Pereiopods: absent.
Pleon (Fig. 1b): with 5 segments; somites 2–5 with pair of posteromedian simple setae; somites 3–5 with posterolateral processes; somites 2–3 with dorsolateral processes; sixth somite merged with telson; pleopods absent.
Telson (Fig. 1k): bifurcated; each furca with 3 lateral spines and 2 simple setae; median shorter than others; inner margins with 3 + 3 stout spinulate setae separated by medial sinus.
description: Published as part of Bochini, Gabriel L., Santos, Rafael C., Zara, Fernando J., Costa, Rogério C. & Mantelatto, Fernando L., 2022, The first zoeal stage of the deep-sea crab Tetraxanthus rathbunae (Brachyura Pseudorhombilidae): a morphological description, pp. 46-54 in Zootaxa 5174 (1) on pages 47-49, DOI: 10.11646/zootaxa.5174.1.3, http://zenodo.org/record/6973012