Petrarctus veliger Holthuis, 2002

Yang, Chien-Hui, Lin, Chia-Wei & Chan, Tin-Yam, 2014, Additional slipper lobsters of the subfamily Scyllarinae Latreille, 1825 (Crustacea, Achelata, Scyllaridae) from Taiwan, Zootaxa 3852 (3), pp. 336-346 : 343-345

Petrarctus veliger Holthuis, 2002

( Figs. 5 , 6 D)

Petrarctus veliger Holthuis 2002: 541 , figs. 15–17 (type locality: Andaman Sea, south Burma).—Chan 2010: 161.

Material examined. Yilan County, Dasi fishing port, commercial trawler, 24 Dec 2003, 1 female 19.4 mm cl (NMMBCD4008).

Diagnosis. Body robust and rough, with tubercles high and depressions deep. Rostrum sharp. Pregastric tooth absent. Gastric and cardiac teeth highly elevated as large triangles. Anterior and posterior branchial carinae well developed, separated by wide but shallow cervical groove. Medial incision at posterior margin of carapace deep. Abdomen with wide transverse grooves and high median carinae. Articulating surfaces of abdominal tergites without setose grooves. Non-articulating surface of abdominal tergites distinctly covered with many flattened tubercles on either side of transverse grooves. Abdominal median carinae highest on somite III. Posterior margins of abdominal tergites I–III medially incised, that at tergite III rather weak. Abdominal pleura II–IV terminating in blunt angle. Anterior margin of antennal segment VI with 6 long blunt teeth. Antennal segment IV without additional ridge, anterior and outer margins each bearing 3 or 4 teeth. Dactylus of pereiopod II longest in all pereiopods. Anterior end of thoracic sternum with deep “U”-shaped notch followed by a medial suture, lateral border highly elevated. Thoracic sternites without median tubercle.

Coloration. Body generally dark greenish brown. Anterior half of carapace covered with a large wide “V”- shaped white marking. Eyes dark brown. Abdominal tergite I orange with large median black spot.

Distribution. Known with certainty from the Andaman Sea, the Philippines and Taiwan, at depths of 69– 300 m.

Remarks. The genus Petrarctus includes four species of which two were reported from Taiwan, namely P. brevicornis (Holthuis, 1946) and P. rugosus (H. Milne Edwards, 1837) . Petrarctus veliger can be readily distinguished from the other species of the genus in the gastric and cardiac teeth being excessively high and triangular. The coloration of the present species is known for the first time and differs from P. brevicornis and P. rugosus in the abdominal tergite I being orangish with a median black spot instead of evenly bluish (see Chan & Yu 1986, 1993).

Figures

FIGURE 5. Petrarctus veliger Hothuis, 2002, female 19.4 mm cl (NMMBCD 4008): A, carapace, dorsal view; B, dorsal part of carapace, lateral view; C, thoracic sternum. Scales = 5 mm.

FIGURE 6. A, Bathyarctus rubens (Alcock and Anderson, 1894), male 14.9 mm cl (NTOU M 01283); B, Chelarctus aureus (Holthuis, 1963), female 14.3 mm cl (NTOU M 01288); C, Crenarctus bicuspidatus (De Man, 1905), male 11.8 mm cl (NMMBCD 4007); D, Petrarctus veliger Hothuis, 2002, female 19.4 mm cl (NMMBCD 4008).