Pullosquilla decocki, Ahyong, 2025

Pullosquilla decocki sp. nov.

( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 )

Type material. HOLOTYPE: AM P109142 , female (TL 15 mm), Port Benier Bay, Aoré Island , Vanuatu, 15°34.3’S, 167°11.9’E, 1–3 m, coarse coral sand, Warén dredge, LD31, 14 October 2006. GoogleMaps

Diagnosis. Raptorial claw propodus longer than carapace; dactylus with 23 or 24 teeth. Abdominal somite 6 posterior margin unarmed. Uropodal protopod with 1 spine above articulation with exopod. Pereopods 1 and 2 proximal article each with outer spine only. Telson posteromedian lobe subquadrate; ventral surface smooth, without spinules. Uropodal protopod inner primary spine longer than the outer primary spine.

Description of holotype. Eye not extending beyond antennular peduncle article 3 ( Fig. 1A View FIGURE 1 ); cornea subglobular, inclined laterally on stalk, stalk not concealed by rostral plate. Ophthalmic somite ventral surface smooth, anterior margin with short median point ( Fig. 1C View FIGURE 1 ); ocular scales fused into narrow, blunt elongated process ( Fig. 1A View FIGURE 1 ).

Antennular peduncle 0.56CL. Antennular somite dorsal processes with acute apices, spiniform, directed almost anterolaterally ( Fig. 1A, B View FIGURE 1 ). Antennal protopod dorsally unarmed; without papillae ( Fig. 1D View FIGURE 1 ). Antennal scale length 2.65× width, 0.20CL.

Rostral plate triangular, slightly wider than long, widest basally; margins straight; dorsum smooth ( Fig. 1A View FIGURE 1 ). Carapace anterolateral angles broadly rounded.

Raptorial claw ( Fig. 1E View FIGURE 1 ) dactylus occlusal margin with 23 or 24 teeth (including terminal tooth), outer margin broadly curved, with obtuse proximal lobe. Propodus longer than carapace; occlusal margin fully pectinate, with 4 proximal movable spines; PI 86. Carpus dorsal margin terminating in short point, directed ventrally. Merus shorter than carapace, inferodistal angle blunt, obtusely rounded. Ischium about 0.8× merus length, with strong inferodistal spine.

Mandibular palp absent. Maxillipeds 1–5 each with epipod. Maxilliped 5 basal article without ventrally directed spine.

Thoracic somite 5 lateral process obsolete, lacking ventrally directed spine. Thoracic somites 6–8 lateral process subtruncate to broadly rounded ( Fig. 1F View FIGURE 1 ). Thoracic sternite 8 keel bluntly angular ( Fig. 1G View FIGURE 1 ).

Pereopods 1–3 ( Fig. 1H–J View FIGURE 1 ) proximal article each with posterior spine on outer margin; inner margin unarmed. Pereopod 1 endopod distal article elongate-subcircular. Pereopod 2 endopod distal article ovate, about twice as long as wide. Pereopod 3 endopod distal article sub-oblong, length about 2.5× width.

Abdominal somites 1–5 smooth; posterior margin unarmed; posterolateral corners bluntly rounded, unarmed ( Fig. 1K, L View FIGURE 1 ). Abdominal somite 6 smooth, dorsal surface unarmed, lacking carinae; posterolaterally rounded, unarmed ( Fig. 1K View FIGURE 1 ); with short spine and blunt, obtuse projection anterior to uropodal articulation ( Fig. 1L, M View FIGURE 1 ); sternum posterior margin unarmed, slightly concave.

Telson thick, width about 1.5× length; smooth dorsally; margin with 3 pairs of primary teeth (submedian, intermediate, lateral) ( Fig. 1K, L, N View FIGURE 1 ); submedian primary teeth slender, movable, straight; with 6 or 7 spiniform submedian denticles in transverse row either side of midline; with 4 spiniform ‘intermediate’ denticles, subequal in length; lateral denticle spiniform, subequal in size to lateral primary tooth. Intermediate and lateral primary teeth slender, spiniform. Posterodorsal surface ( Fig. 1K, L View FIGURE 1 ) with false eave partially overhanging marginal teeth and denticles, formed from bluntly rounded, subquadrate median lobe flanked by bluntly angular projection above base of submedian primary teeth, median lobe and flanking lobes separated by wide V-shaped notch. Ventral surface unarmed ( Fig. 1N View FIGURE 1 ).

Uropodal protopod terminal spines slender, dorsally flattened, ventrally carinate, outer spine shorter than inner spine ( Fig. 1M View FIGURE 1 ); with dorsal spine above articulation with exopod ( Fig. 1K, L View FIGURE 1 ); without ventral spine anterior to endopod articulation ( Fig. 1M View FIGURE 1 ). Exopod proximal article outer margin with 4 movable spines, distalmost spine reaching slightly beyond distal half of distal article; inner margin almost straight, posteromesial margin rounded, with 3 stiff setae; small distoventral spine. Exopod distal article longer than proximal article. Endopod length about 3.3× width, dorsal surface with strong proximal fold.

Colour in life ( Fig. 2 View FIGURE 2 ). Translucent overall; carapace, thorax and abdomen speckled with patches of white chromatophores, densest laterally and along midline and with scattered black-brown chromatophores and minute red chromatophores in 2 rows either side of midline and along lateral margins; raptorial claws and uropods with scattered white chromatophores. ‘Ripe’ orange gonads visible through cuticle along abdominal midline in female holotype.

Etymology. Named for Wim Decock on occasion of his retirement from the Flanders Marine Institute (VLIZ). Wim has been a core member of the WoRMS (World Register of Marine Species; www.marinespecies.org) data management team for more than 16 years. It is a pleasure to name the new species in his honour.

Measurements. TL 15 mm, CL 2.64 mm, antennular peduncle length 1.47 mm, antennal scale length 0.53 mm, raptorial claw propodus length 3.08 mm.

Distribution. Known only from Vanuatu; 1– 3 m.

Remarks. Pullosquilla decocki sp. nov., the fifth species of the genus, most closely resembles P. malayensis and P. litoralis in sharing a similar arrangement of the intermediate denticles of the telson, absence on row of spines along the margin of the false eave and patch of ventral spines on the telson (as present in P. thomassini ), and in having the inner primary spine of the uropodal protopod longer than the outer primary spine (outer spine longer in P. pardus ). From P. litoralis , P. decocki is readily distinguished by the subquadrate posteromedian lobe on the telson (bluntly subtriangular in P. litoralis ) and longer raptorial claw with more dactylar teeth in which the propodus of the new species is longer than the carapace (PI 86 vs 119–128; 23 or 24 teeth vs 9–12; Ahyong 2001), and the slender ocular scales (equilaterally triangular in P. litoralis ). Pullosquilla decocki and P. malayensis have similar raptorial claws, both species having a propodus longer than the carapace and with overlapping armature of the dactylus (23 or 24 vs 15–26 teeth; Ahyong & Erdmann 2003). Owing to the brief type description by Manning (1968) of P. malayensis ( Fig. 3 View FIGURE 3 ), the species is refigured here from the type material for comparison with P. decocki . From P. malayensis , P. decocki differs in having only an outer spine on the proximal article of pereopods 1 and 2 ( Fig. 1H–J View FIGURE 1 ) (inner and outer spines present in P. malayensis ; Fig. 3D–F View FIGURE 3 ), ocular scales fused into a slender process ( Fig. 1A View FIGURE 1 ) (equilaterally triangular in P. malayensis ; Fig. 3A View FIGURE 3 ) and a subquadrate versus bluntly triangular posteromedian lobe on the telson (in dorsal view) ( Fig. 1K View FIGURE 1 , 3G View FIGURE 3 ).