Holthuija Ng & Forges 2015, n. gen.
Creators: name: Ng, Peter K. L.
name: Forges, Bertrand Richer De
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Majidae
Holthuija

description: Holthuija n. gen.   
 Diagnosis. Carapace ovate; dorsal surface inflated, regions distinct, covered by granules or spines; gastric and branchial regions clearly delimited by grooves (Figs. 24–26). Intestinal region without median spine (Figs. 24–26). Pseudorostral spines relatively long, diverging, forming a V (Figs. 24, 25, 37D–J). Supraorbital eave large, anterior part strongly expanded, foliaceous, margin convex; spine; antorbital spine long, sharp (Fig. 37D–J). Intercalated spine distinct, separated from supraorbital eave and postorbital spine by distinct gaps; postorbital spine strong, lobiform; hepatic region with 1 strong spine, much shorter than postorbital spine; 1 tubercle below (Fig. 37D–J). Lateral carapace margin with 3 large spines, 1 branchial spine (Figs. 24, 25). Posterior carapace margin with 2 distinct median spines (Figs. 24, 25). Eyes relatively long, slender, with ovoid cornea (Fig. 37D–J). Antennal flagellum short, slender. Basal antennal article longer than broad, rectangular; surface with several tubercles, with 2 spines distally; inner and outer lateral margins with low granules; proximal outer angle rounded; antero-external crested rim of antennular fossa overlaps distal part of basal antennal article by about a third of its width (Fig. 40D–I). Epistome slightly wider than long, anterior margin with 2 low lobes and granular extension below each; posterior margin composed of 4 rectangular plates separated by shallow fissures (Figs. 40D–I, 42C–E). Suborbital margin separated from basal antennal article and margin of postorbital tooth by fissures (Fig. 40D–I). Outer surface of third maxilliped covered by short setae; ischium subrectangular, slightly longer than broad; postero-external angle of merus relatively broad, “inserted” into shallower concavity on outer margin of ischium; antero-internal part of ischium rounded, auriculiform (Fig. 46A–F). Male chelipeds relatively short in adult males, surfaces of merus and carpus almost smooth; carpus elongate; propodus of palm elongated, not inflated, curved, smooth, palm longer than fingers; fingers long, slender, gently curved, with small basal gape when closed (Figs. 24, 25, 54D–I). Ambulatory legs relatively short, slender; merus without dorsal subdistal spine; dactylus elongate, curved, covered with long setae except for corneous tip (Figs. 24, 25, 56C–G). Thoracic sternum wide; surfaces of somites 5–8 with numerous rounded tubercles and granules; sternites 3 and 4 with obliquely longitudinal depressions; margin between sternites 2 and 3 demarcated by deep notch; anterior margin of sterno-abdominal cavity forming complete rim (Figs. 50D–I, 52I). Male abdomen subrectangular, with 6 free somites and telson; somites 3 and 4 subequal to or wider than somites 6 and telson (Fig. 50D–I). Male press-button abdominal locking mechanism submedian in position on sterno-abdominal cavity (Fig. 52I). Female abdomen dome-shaped, covering most of thoracic sternum. G1 long, relatively stout, almost straight or gently curved, distal part with scattered short setae (Fig. 27).   
 Type species. Maia miersii Walker, 1887, by present designation.   
 Etymology. The name is derived from an arbitrary combination of the name Holthuis, with the genus name Maja. This honours the major contribution by the late Lipke B. Holthuis in resolving the convoluted nomenclature of the genus. Gender feminine.   
 Remarks. Six species are included in Holthuija n. gen. H. miersii (Walker, 1887), H. suluensis (Rathbun, 1916), H. pauli n. sp., H. cognata n. sp., H. aussie n. sp. and H. poorei n. sp. These species are all easily distinguished by their prominently foliate supraorbital eave, which is the most expanded in all the genera treated here. All species also have a strongly granulated carapace surface, epistome, suborbital and pterygostomial regions, third maxilliped, thoracic sternum and abdomen. The suborbital tooth is also sharply separated from the postorbital tooth by a distinct fissure; and the G1 is generally simple, with a simple distal part and only scattered short setae.
description: Published as part of Ng, Peter K. L. & Forges, Bertrand Richer De, 2015, Revision of the spider crab genus Maja Lamarck, 1801 (Crustacea: Brachyura: Majoidea: Majidae), with descriptions of seven new genera and 17 new species from the Atlantic and Indo-West Pacific, pp. 110-225 in Raffles Bulletin of Zoology 63 on page 160, DOI: 10.5281/zenodo.5384590