Phylladiorhynchus nudus Macpherson, 2008

Rodríguez-Flores, Paula C., Macpherson, Enrique & Machordom, Annie, 2021, Revision of the squat lobsters of the genus Phylladiorhynchus Baba, 1969 (Crustacea, Decapoda, Galatheidae) with the description of 41 new species, Zootaxa 5008 (1), pp. 1-159 : 95

Phylladiorhynchus nudus Macpherson, 2008

( Fig. 33F )

Phylladiorhynchus nudus Macpherson, 2008: 294 , fig. 2 (Dampier Archipelago, W Australia, 2–5 m).— Baba et al., 2008: 176 (compilation).— Schnabel & Ahyong, 2019: 304 (key).

Type material. Paratype. Western Australia. Dampier Archipelago. Stn DA 3/99/61, 20.5776°S, 116.6620°E, 3–5 m, 14 September 1999: 1 M 2.7 mm ( WAM C25991) .

Other material. Western Australia. Montgomery Island. Stn 22/K09-adhoc, 15.944317°S, 124.27330°E, no depth, 22 October 2009: 1 ov. F 2.2 mm ( WAM C44013) .— Stn 24/K09-T2, 16.014417°S, 124.173100°E, no depth, in sponge, 23 October 2009: 2 M 1.2–1.9 mm ( WAM C44014) .— Stn 27/K09-Q3, 15.0000°S, 124.0000°E, no depth, 24 October 2009: 1 F 2.2 mm ( WAM C44038) .— Long Reef. Stn 50/K10-Q2, 13.91545°S, 125.774317°E, 2 m, 22 October 2010: 1 M 2.3 mm, 1 ov. F 2.4 mm ( WAM C46587) , 1 F 2.2 mm ( WAM C46583) .— Adele Island. Stn 07/K09-Q3, 15.49123°S, 123.16330°E, 0 m, 5 October 2009: 2 F 1.4–1.8 mm ( WAM C44006) .— Stn 11/K09- T1, 15.581583°S, 123.163200°E, 0–3.5 m, 17 October 2009: 1ov. F 2.3 mm ( WAM C44003) .— Ningaloo Reef. 22.7473°S, 113.0752°E, 11 m, 1 May 2009: 1 M 2.5 mm ( UF22848 ) .

Diagnosis. Rostrum with subapical spines; lateral margins straight. Epigastric ridge of carapace unarmed, medially interrupted; anterior branchial margin of carapace with 2 spines; anterior protogastric and mesogastric ridges not interrupted medially; anterior metagastric ridge medially interrupted. Pterygostomian flap with small spine on upper margin. Anterior margin of thoracic sternite 3 slightly convex, with lateral projections Antennular article 1 with 5 spines; distomesial spine small, similar to lower distolateral spine. Antennal article 1 mesial process distally falling well short of second lateral antennular spine; article 2 with distomesial and distolateral spines subequal; article 3 with small distolateral spine. Flexor margin of Mxp3 merus with 1 prominent spine. P2–4 dactylus flexor margins with 5–6 well-developed dactylar spines, each with 1 spinule.

Eggs: Ov. F carried approximately 30– 40 eggs of 0.4–0.5 mm diameter.

Live colour. Unknown.

Genetic data. COI and 16S, Table 1.

Distribution. The species was described from the Dampier Archipelago (northwestern Australia) ( Macpherson, 2008). The new records extend its distribution range along the Western Australia, between 0 and 11 m.

Remarks. Phylladiorhynchus nudus belongs to group of species having the epigastric ridge unarmed, the carapace and the pleon ridges elevated, upraised, and dactylar spines on the flexor margin of the P2–4 dactyli. The group includes P. marina , P. jeffkinchi , P. nudus and phanus . However, P. nudus can be easily distinguished from the rest of the species of this group by the presence of a spine on the upper margin of the pterygostomiam flap, whereas this margin is unarmed in the other species. The genetic divergences between P. nudus and other species were always higher than 14% for COI and 13% for 16S.

Figures

FIGURE 33. Rostrum, dorsal view. A, Phylladiorhynchus laureae n. sp., paratype female 1.7 mm (MNHN-IU-2019-2635). B, P. lini n. sp., holotype female 2.2 mm. C, P. lynceus n. sp., holotype ovigerous female 2.0 mm (MNHN-IU-2019-2593). D, P. marina n. sp., male 1.5 mm (MNHN-IU-2019-2653). E, P. medea n. sp., paratype male 2.1 mm (MNHN-IU-2014-13795). F, P. nudus Macpherson, 2008, ovigerous female 2.4 mm (WAM C46587). G, P. nui Schnabel & Ahyong, 2019, male 6.5 mm (MNHN-IU-2019-2595). H, P. orpheus n. sp., paratype male 1.9 mm (UF33962). I, P. paula n. sp., paratype male 2.3 mm (MNHN-IU-2019-2699). J, P. penelos n. sp., paratype male 3.3 mm (UF1224). K, P. pepei n. sp., holotype male 3,2 mm (MNHN-IU-2016-486). L, P. phanus n. sp., paratype male 2.1 mm (MNHN-IU-2019-2687). Scale bars = 1 mm.