Paranchistus liui, Li & Bruce & Manning*, 2004

Li, Xinzheng, Bruce, Alexander J. & Manning *, Raymond B., 2004, Some Palaemonid Shrimps (Crustacea: Decapoda) From Northern South China Sea, With Descripitions Of Two New Species, Raffles Bulletin of Zoology 52 (2), pp. 513-553 : 535-538

Paranchistus liui , new species

( Figs. 21-23 )

Material examined. – Holotype - female, CN 21-31 , [21ºN, 108ºE], 30m, AT, coll. Z. Tang, 24 Jan.1959.

Paratypes – 1 male, CN Y95 B-61, [19º45’N, 109ºE], 24.4m, sandy mud, AT, coll. Z. Fan, 18 Apr.1960 ; 1 female (ovig), CN Y5 B-33, [19º45’N, 107º30’E], 51.5m, sand, AT, coll. X. Ma, 4 Dec.1959 .

Diagnosis. – Rostrum slightly ventral directed, dorsal and ventral margins subparallel, apex blunt, with 1 distodorsal tooth and 1 apical tooth which situated at the below middle of the apex. Carapace with lower orbital angle produced anteriorly and rounded. First pereiopods with cutting edges of fingers entire, not pectinate. Second pereiopods with the tips of fingers crossed. Third pereiopods with dactyl compressed, unguis not flattened, with sparse fine tubercles on extensor surface, ventral margin simple, not biunguiculate, corpus with distal margin slightly deeper than base of unguis.

Description. – Small sized shrimp. Body subcylindrical, smooth.

Rostrum almost reaching end of first segment of antennular peduncle, directed slightly ventrally, compressed but gradually broadening laterally proximally, dorsal and ventral margins subparallel; apex blunt, with setae and 2 teeth - one distodorsal, the other placed just below middle of blunt apex, distoventral angle rounded. Carapace smooth; lower orbital angle produced anteriorly, rounded; antennal spine small, placed some distance below orbit, marginal, not beyond the lower orbital angle; hepatic spine small, movable and placed slightly lower than antennal spine; anterolateral angle of carapace rounded.

Abdomen smooth; pleura of anterior five somites broadly rounded, sixth somite slightly longer than fifth, with acute posterolateral and round posteroventral angles.

Telson about 1.5 times as long as sixth abdominal somite, lateral margins almost straight, with 2 similar pairs of small submarginal dorsal spines on posterior 0.4 length of the telson, posterior pair slightly nearer to anterior pair than to posterior margin of telson; posterior margin bearing 3 pairs of spines, outer pair extremely short, as in dorsal spines, about 0.25 of length of intermediate pair, intermediate pair long and robust, 0.16 times as long as the length of telson, submedian pair slender, about 0.75 as long as intermediate pair.

Eyes well developed, cornea hemispherical, shorter and narrower than eyestalk, eyestalk slightly longer than broad, ocellus distinct.

Antennule with first segment broad, outer margin slightly convex, anterolateral spine over-reaching adjacent convex anterior margin of segment; stylocerite not reaching middle of segment, apex somewhat rounded, not acute. Second segment shorter and broader than third. Two rami of upper antennular flagellum fused proximally for 4 segments, free part of shorter ramus consisting of 5 segments, slightly shorter than half of fused portion.

Antenna with scaphocerite distinctly over-reaching antennular peduncle; outer margin slightly convex, distolateral tooth not reaching end of lamella; lamella broad.

Mandible with apex of incisor process broken off and missing; apical surfaces of molar process right and left oblique - right process oblique anteriorly, with 4-5 blunt teeth, left process oblique posteriorly, with 5-6 teeth—so that they oppose with each other. Maxillula with upper lacinia somewhat pentagonal, lower lacinia oval; palp with apex concave. Maxilla with distally rounded non-setose palp, shorter than endite; endite bilobed, with numerous setae distally; scaphocerite moderately broad. First maxilliped normal. Second maxilliped with distal margin of terminal segment straight. Third maxilliped with the terminal segment 0.75 length of penultimate, exopod just reaching to distal end of antepenultimate segment; latter segment with ischiomerus and basis indistinctly separated.

First pereiopod with chela subcylindrical; fingers approximately equal to palm in length, cutting edges entire, not pectinate, with several transverse rows of setae on outer surface; carpus about 1.5 times as long as chela, broadening anteriorly, with tuft of setae distoventrally; merus as long as carpus; ischium more than half of merus length; basis about half as long as ischium, with row of long setae along the flexor margin; coxa with oval lobe bearing long setae apically. Second pereiopods robust and equal in size, over-reaching scaphocerite with about half of chela; fingers short, about 0.33 as long as palm, tips crossing, movable finger with one strong tooth on cutting edge, fixed finger bearing 6 small teeth on cutting edge, distal tooth larger than other teeth; carpus shorter than fingers, anterior margin entire; merus 0.33 as long as chela; ischium equal to merus length. Third pereiopods short and robust; dactyl compressed, unguis not flattened, with sparse fine tubercles on extensor surface, corpus with distal margin slightly deeper than base of unguis; propodus 5 times as long as dactyl, with 1 distal and 1 subdistal spine on flexor margin; carpus 0.67 as long as propodus; merus broader and longer than propodus; ischium stout, slightly shorter than propodus. Fifth pereiopods slender and shorter than third; propodus longer than merus, with distoventral spine.

Uropods with protopodite posterolaterally acute, endopod over-reaching tips of posterior marginal telson spines, exopod with outer margin indistinctly convex, bearing lateral movable spine, lacking lateral fixed spine.

Measurements (in mm). – Holotype: CL, 3.3; carapace and rostrum, 4.1; total body length including rostrum, 10; second pereiopod: dactyl, 0.75: chela, 3: carpus, 0.6: merus, 1: ischium, 0.85.

Coloration and host. – No data.

Etymology. - The specific name is given in honor of Prof. J. Y. Liu, carcinologist of the Institute of Oceanology, Chinese Academy of Sciences, Qingdao.

Remarks. – The species is most closely related to P. ornatus Holthuis, 1952a . Its small size, configuration of the rostrum, entire cutting edge of the chela of the first pereiopods, simple dactyl with the distal margin of corpus slightly deeper than base of unguis in the third pereiopods, distinguish P. liui from P. ornatus and other species in the genus.

Figures

Fig. 21. Paranchistus liui, new species. a, body, lateral view; b, anterior region of carapace and rostrum, lateral view; c, carapace and anterior appendages, dorsal view, d, eye.

Fig. 22. Paranchistus liui, new species. a, antennule; b, antenna; c, mandible; d, maxillula; e, maxilla; f, 1st maxilliped; g, 2nd maxilliped; h, 3rd maxilliped.

Fig. 23. Paranchistus liui, new species. a, 1st pereiopod; b, same, chela; c, major (left) 2nd pereiopod; d, same, fingers; e, minor (right) 2nd pereiopod; f, 3rd pereiopod; g, 5th pereiopod; h, telson and uropods, dorsal view.