Trizocheles Forest 1987
Creators: name: Mclaughlin, Patsy A.
name: Lemaitre, Rafael
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Pylochelidae
Trizocheles

description: Genus Trizocheles Forest, 1987
Trizocheles spinosus spinosus (Henderson, 1888)
Pylocheles spinosus Henderson, 1888: 101, pl. 11, fig. 1.
Trizocheles spinosus spinosus. — Forest, 1987: 202, figs. 47d, 66g, 69c, 70.
Material examined. Twenty-six specimens, cl (including rostrum) = 1.8–2.1 mm; 10 dissected. All specimens hatched from single ovigerous female at time of preservation; additional eggs less developed. Female (sl = 6.6 mm), R/V Kaharoa stn Z9852, 37º28.15’S, 177º06.71’E, 250–310 m, 5 Jun 1999 (NIWA 43797).
Description. Yolk granules usually present.
Carapace (Fig. 1 a). Globoid, lacking spines and setae, posterior margins rounded; rostrum approximately 0.2 of carapace length, moderately slender, frequently directed somewhat downward.
Eyes. Stalked, corneas large.
Antennule (Fig. 1 b). Biramous, with protopod elongate, unsegmented; endopod varying from nearly equal in length to approximately twice length of exopod, naked or with 1 terminal seta; exopod varying from naked to bearing 1 short terminal seta and 3 or 4 aesthetascs, 1 aesthetasc on inner margin.
Antenna (Fig. 1 c). Biramous; protopod unsegmented, with small spine at endopodal junction and larger spine at scaphocerite junction; base of protopod sometimes enlarged, with internally directed lobe of future antennal gland orifice apparent; endopod varying from approximately half length of scaphocerite to nearly equal to tip of distolateral spine. Scaphocerite with 11 or 12 setae, often only partially evaginated, on inner margin, upper margin with or without small spine; distolateral spine subdistal in origin and very prominently bifid.
Mandible (Fig. 1 d). Varying from indistinguishably fused to epistome to subquadrate in structure with unsegmented, naked palp.
Maxillule (Fig. 1 e). Often indiscernible, occasionally with buds of endites and endopod developed, all lacking setae.
Maxilla (Fig. 1 f). Varying from bilobed bud to moderately well developed appendage with bilobed coxal and basial endites, and scaphognathite, endopod apparent or not; all lacking setae.
First maxilliped (Fig. 1 g). Protopod unsegmented; exopod elongate; endopod varying from rudimentary to subequal in length to exopod, both lacking setae and segmentation.
Second maxilliped (Fig. 1 h). Protopod unsegmented; exopod elongate, varying from unsegmented to incompletely 2-segmented; endopod varying from unsegmented and subequal in length to exopod to appreciably shorter than exopod and faintly 4-segmented, setae lacking.
Third maxilliped (Fig. 1 i). Protopod unsegmented; exopod elongate, varying from faintly to incompletely 2-segmented; endopod unsegmented, varying from rudimentary to moderately well developed bud.
Chelipeds (Fig. 2 a). Chela with dactyl distinguishable, articulation with palm usually not apparent; carpus and merus delineated, unarmed; setae entirely lacking.
Pereopods 2 and 3 (Fig. 2 b, c). Dactyls, propodi, carpi and meri varying from partially to clearly delineated, no terminal claws apparent; setae entirely lacking.
Pereopod 4 (Fig. 2 d). Dactyl semichelate; remaining segments partially to clearly delineated; setae entirely lacking.
Pereopod 5 (Fig. 2 e). Dactyl partially to clearly delineated, simple, terminal; remaining segments partially to clearly delineated; setae entirely lacking.
Pleon (Fig. 2 f). Six-segmented, with telson clearly separated; pleomeres 1–4 and 6 unarmed, pleomere 5 with pair of moderately prominent posterolateral spines; uniramous or weakly biramous pleopod buds present on pleomeres 2–5; pleomere 6 with uni- or biramous uropod buds.
Telson (Fig. 2 f, 4h). Short and moderately stout; terminal margin with broad V-shaped median cleft and 8 + 8 processes, all articulated, 3–8 each with long, fine marginal setae, fourth process longest.
description: Published as part of Mclaughlin, Patsy A. & Lemaitre, Rafael, 2008, Larvae of two species of Trizocheles (Decapoda: Anomura: Paguroidea: Pylochelidae: Trizochelinae), description of the adult of one, and preliminary implications of development on pylochelid phylogeny, pp. 52-68 in Zootaxa 1911 on pages 53-56, DOI: 10.5281/zenodo.184552