A revision of the genus Prionocrangon (Crustacea: Decapoda: Caridea: Crangonidae) Author Kim, Jung Nyun Author Chan, Tin-Yam text Journal of Natural History 2005 2005-04-18 39 19 1597 1625 http://dx.doi.org/10.1080/00222930400016788 journal article 10.1080/00222930400016788 1464-5262 5214903 Prionocrangon formosa sp. nov. ( Figures 8 , 11B ) Material examined Taiwan. TAIWAN 2001, commercial trawler, stn CP 104, 24 ° 48.869N , 122 ° 5.319E , 365– 447 m , 19 May 2001 , 1♀ (CL 4.9 mm ), holotype , NTOUM00591 . Description Rostrum very short, extending only to tip of antennal spine and 0.07 times as long as carapace ( Figure 8A ). Mid-dorsal carina of carapace armed with six spines ( Figure 8A ). Fourth and fifth abdominal somites without median carina ( Figure 8B ); sixth somite 0.57 times as long as carapace, posterior margin of posterolateral process truncate and armed with minute denticle ( Figure 8E ). Telson slightly shorter than sixth abdominal somite ( Figure 8D ), 0.53 times as long as carapace, posterior half slightly convergent; posterior margin rounded but armed with minute median denticle, bearing three pairs of long spines ( Figure 8F ). Eyestalks drawn out to bluntly cylindrical extremities ( Figure 8G, H ), curving ventrally and reaching in between antennules ( Figure 8C ). Antennular peduncle with proximal segment relatively short, 0.57 times as long as carapace ( Figure 8B ). Stylocerite with tip elongate and sharp ( Figure 8C ). Scaphocerite overreaching distal margin of proximal segment of antennular peduncle, 0.63 times as long as carapace ( Figure 8B ). Palm of first pereopod moderately slender, 4.13 times as long as wide ( Figure 8I ). Dactyli of fourth and fifth pereopods relatively long, 0.70 times as long as propodi ( Figure 8J ). Only holotype female known, endopod of second pleopod about 0.25 times as long as exopod ( Figure 8L ); endopods and protopods of pleopods without lateral lobe or distoventral projection ( Figure 8K, L ). Figure 8. Prionocrangon formosa sp. nov. , holotype female (CL 4.9 mm) from Taiwan, TAIWAN 2001 stn CP 104. (A) Entire animal, lateral; (B) same, dorsal; (C) anterior part of carapace, eyes, basal parts of antennule and antenna, dorsal; (D) sixth abdominal somite and tailfan, dorsal; (E) posterolateral process of sixth abdominal somite, lateral; (F) telson, dorsal; (G) eyes, dorsal; (H) same, lateral; (I) chela and carpus of right pereopod, dorsal; (J) dactylus and propodus of right fourth perepod; (K) right first pleopod, ventral; (L) right second pleopod, ventral. Size Only one female CL 4.9 mm known. Distribution Known only from north-eastern Taiwan between 365 and 447 m depth . Colour in life Entire animal ivory white and somewhat translucent ( Figure 11B ). Etymology This new species is named after its type locality; Formosa is the old name for Taiwan . Remarks This small specimen from Taiwan shows a close resemblance with P. curvicaulis but is unique in the genus in having a very short rostrum and much less-developed branchiostegal spine (see also ‘‘Remarks’’ under P. curvicaulis ). Although this Taiwanese specimen has a rather small size, it is very unlikely that the shape of the rostrum is size-related since no such variation has been observed in P. dofleini of which many specimens of a large size range have been examined (i.e. CL 3.4–10.7 mm ). Therefore, it seems justified in giving a new name to this short rostrum form.