Periclimenaeus devaneyi, Bruce, 2010

Bruce, A. J., 2010, Periclimenaeus devaneyi sp. nov., from Oahu, Hawai'i (Crustacea: Decapoda: Pontoniinae) *, Zootaxa 2372 (1), pp. 379-388 : 380-387

publication ID	https://doi.org/ 10.11646/zootaxa.2372.1.30
persistent identifier	https://treatment.plazi.org/id/03F58799-965F-FFF8-FF62-3CCE1D0FFE92
treatment provided by	Felipe
scientific name	Periclimenaeus devaneyi
status	sp. nov.

Treatment

Periclimenaeus devaneyi View in CoL sp. nov.

( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Material examined. (i) 1 ov. female, 6B #2, CL 1.4, Kahe Point , Oahu, Hawai'an Islands, 15 June 1976, coll. S.L. Coles, BPBM-S 14813 ; (ii) 1 male, holotype, 5B#3 spm D, CL 1.3, Kahe Point , Oahu, Hawai'an Islands, 21°21’11.0”N, 158°07’54.5”W, 19 June 1976, coll. S.L. Coles, BPBM-S 14814 ; (iii) GoogleMaps ov. female holotype, 10C #3, CL 1.4, Kahe Point , Oahu, Hawai'an Islands, 22 June 1976, coll. S.L. Coles, BPBM-S 14815 ; (iv) 1 ov. female paratype, 6B #1, CL 1.0, Kahe Point , Oahu, Hawai'an Islands, 13 July 1977, coll. S.L. Coles, QM W28904; (v) 1 female, 7C #4, CL 0.9, Kahe Point , Oahu, Hawai'an Islands, 5 August 1977, coll. S.L. Coles, BPBM-S 14816 ; (vi) 1 male, 7B #3, CL 1.05, Kahe Point , Oahu, Hawai'an Islands, 20 January 1976, coll. S.L. Coles, BPBM-S 14817 .

Diagnosis. A small species of Periclimenaeus Borradaile 1915 , with an articulated distoventral spine on the carpus of the ambulatory pereiopods. Rostral dentition 3/0 in both sexes, cutting edge of major second pereiopod dactyl distally minutely denticulate, of minor second pereiopod compressed, subcircular, coarsely dentate, ambulatory dactyls with acute proximal and distal ventral teeth.

Description. Ovigerous female holotype. A very small-sized pontoniine shrimp, of slender build.

Rostrum ( Fig. 1B View FIGURE 1 ) about 0.45 of CL, compressed, slender, horizontal, not reaching distal margin of first segment of antennular peduncle, with 3 slender acute teeth over central half, with sparse interdental setae, tip acute, slightly up-turned, ventral margin mainly straight, non-setose.

Carapace ( Fig. 1A View FIGURE 1 ) smooth, without supraorbital spines, tubercles or ridges, orbit obsolescent, inferior orbital angle obsolete ( Fig. 1C View FIGURE 1 ), antennal spine well developed, marginal, anterolateral angle slightly produced, non-articulate.

Abdomen without special features, first tergite without anteromedian lobe, pleura rounded, sixth segment about 0.42 of CL, 2.0 times longer than deep, posteroventral and posterolateral angles acute.

Telson ( Fig. 1H View FIGURE 1 ) about 1.8 times length of sixth segment, 0.75 of CL, 2.0 times longer than wide, lateral margins convex, posteriorly convergent to rounded posterior margin, 0.35 of anterior width, without apical process, paired dorsal spines at about 0.3 and 0.6 of telson length, posterior pair slightly longer than anterior, about 0.15 of telson length, three pairs of posterior marginal spines ( Fig. 1I View FIGURE 1 ), lateral spines small, shorter than anterior dorsal spines, intermediate spines long, slender, about 0.17 of telson length, submedian spines slender, exceeding intermediate spines, sparsely setulose,

Antennule ( Fig. 1D View FIGURE 1 ) with proximal segment about 2.4 times longer than central width, with small acute ventromedial tooth at half length, lateral margin straight with angular projection over central third, distolateral angle with small acute process, stylocerite short, broad, acute, statocyst normal; intermediate and distal segments short, broad, together about half length of proximal segment, upper flagellum biramous, first two segments fused, shorter free ramus with single segment only, longer ramus with five, about seven groups of aesthetascs, lower flagellum slender, short, with 6 segments.

Antenna ( Fig. 1E View FIGURE 1 ) with basicerite robust, unarmed, with conspicuous antennal gland tubercle medially, carpocerite subcylindrical, about 4.8 times longer than wide, slightly exceeding scaphocerite, merocerite and ischiocerite normal, scaphocerite ( Fig. 1F View FIGURE 1 ) well developed, reaching to distal end of carpocerite, 2.5 times longer than maximal width at about 0.6 of length, lateral margin straight, with acute tooth, not exceeding distal margin of lamella, at about 0.87 of scaphocerite length.

Eye ( Fig. 1G View FIGURE 1 ) with cornea well pigmented, globular, about 0.25 of CL, without accessory pigment spot, stalk as wide as long, tapering slightly distally.

Mouthparts not examined.

Thoracic sternites narrow, unarmed.

First pereiopod ( Fig. 3A View FIGURE 3 ) short, robust, chela ( Fig. 3B View FIGURE 3 ) with palm oval in section about 1.8 times longer than deep, fingers similar, sparsely setose, about 1.1.times palm length, broadly spatulate, cutting edges entire, distally rounded, tips ( Fig. 4G View FIGURE 4 ) with short stout curved tooth flanked by short stout multi-cusped spines ( Fig. 4H View FIGURE 4 ); carpus short, stout, subcylindrical, about 0.9 of chela length, merus subequal to chela length, 4.0 times longer than deep, tapering slightly distally; ischium subequal to carpal length, carpus, basis and coxa without special features.

Second pereiopods well developed, dissimilar and unequal. Major second pereiopod ( Fig. 3C View FIGURE 3 ) very well developed, chela about 2.6 times CL, palm oval in cross section, smooth, 1.7 times longer than deep, tapering slightly distally, fingers ( Fig. 3D, E View FIGURE 3 ) robust, 0.33 of palm length, dactyl about 2.0 times longer than depth, dorsal margin strongly convex, with stout hooked tip distally ( Fig. 4I View FIGURE 4 ), cutting edge with very robust molar process proximally, distal cutting edge deeply concave, central portion minutely serrate, fixed finger about 1.2 times longer than proximal depth, ventrally feebly convex, with stout hooked tip distally, cutting edge with large proximal fossa for reception of dactylar molar process, distal cutting edge thickened, entire; carpus obliquely articulated, about 0.3 of palm length, proximally narrow, distally expanded, unarmed, with large medial lobe; merus ( Fig. 3F View FIGURE 3 ) robust, 0.3 of palm length, slightly longer than carpus, 1.5 times longer than depth, centrally swollen, ventral margin ( Fig. 3G View FIGURE 3 ) with 5 small stout acute anteroverted denticles; ischium subequal to meral length, tapering proximally, length 2.0 times distal width, ventrally unarmed; basis and coxa robust, without special features.

Minor second pereiopod ( Fig. 3G View FIGURE 3 ) with chela about subequal to palm length of major chela, palm oval in cross section, compressed, smooth, 1.9 times longer than deep, slightly tapered distally, dactyl ( Figs 3H View FIGURE 3 , 5A View FIGURE 5 ) about 0.4 of palm length, sub-oval, 1.7 times longer than central depth, compressed, ventrally laminar, dorsal margin thickened, convex, tip expanded forming a broad blunt tooth, cutting edge convex with seven teeth, very small proximally becoming very large distally, separated by deep notches, distal tooth confluent with dactylar tip, fixed finger about 1.1 times longer than proximal depth, tip strongly up-curved, robust, acute, cutting edge concave, sharp, entire; proximal segments similar to major chela but smaller, merus ( Fig. 3I View FIGURE 3 ) with 4 ventral denticles, otherwise unarmed.

Third pereiopod ( Figs 3J View FIGURE 3 , 4J View FIGURE 4 )) short, robust; dactyl ( Fig. 4K View FIGURE 4 ) compressed, about 0.3 of propod length, unguis distinctly demarcated, stout, curved, twice as long as basal width, 0.65 of dorsal corpus length, unarmed, corpus 1.13 timed longer than basal width, dorsal margin convex, ventral margin sharp, strongly concave, with short acute erect distal accessory tooth, with small blunt proximal tooth with slender styliform terminal process, with paired distal sensory setae medially and laterally; propod robust, sparsely setose, 0.4 of CL, about 2.8 times longer than proximal depth, tapering slightly distally, with pair of stout distoventral spines ( Figs 3K View FIGURE 3 , 4K View FIGURE 4 , 5C View FIGURE 5 ), larger spine about 0.5 of distal propod width, ventral margin with 1 spine close to distoventral spines and 1 spinule at about one third of propod length; carpus stout, about 1.3 times propod length, distoventral angle with large mobile spine ( Fig. 5C View FIGURE 5 ), about 1.7 times longer than distoventral propodal spine; merus robust, 0.9 of carpal length, 2.2 times longer than wide, slightly tapering distally, unarmed; ischium 0.9 of meral length, 2.0 times longer than distal width, tapering proximally, unarmed, basis and coxa without special features.

Fourth and fifth pereiopods ( Fig. 3L View FIGURE 3 ) similar to third but more elongate; fifth dactyl ( Fig. 5C View FIGURE 5 ) without distal accessory tooth, with propod 1.3 times length of carpus, 4.2 times longer than proximal depth, with single distoventral spine ( Fig. 3M View FIGURE 3 ) and numerous serrulate distolateral spines, carpus with strong distoventral spine.

Pleopods of female holotype without special features; basipodite with one distal ovigerous seta, three proximal ovigerous setae.

Uropod ( Fig. 1J View FIGURE 1 ) with protopod laterally unarmed, exopod broad, about 2.4 times longer than central width, lateral margin straight, non-setose, with strong acute distolateral tooth with well developed mobile spine medially, diaeresis indistinct, endopod more slender, about 3.0 times longer than central width, slightly exceeding exopod.

Ova small and few, about 8 or 9.

Mouthparts (paratype, female (v)): Mandible ( Fig. 2A View FIGURE 2 ) without palp; molar process ( Fig. 4B View FIGURE 4 ) slender, subcylindrical, feebly dentate distally; incisor process ( Fig. 4A View FIGURE 4 ) normal, distally oblique, with three small acute teeth.

Maxillula ( Fig. 2B View FIGURE 2 ) with simple palp ( Fig. 4C View FIGURE 4 ) with small distoventral setiferous tubercle, upper lacinia ( Fig. 4D View FIGURE 4 ) suboval, distal margin slightly truncate with 4 short stout simple spines and several slender simple spines, lower lacinia tapering distally with few slender serrulate spines only.

Maxilla ( Fig. 2C View FIGURE 2 ) with endopod ( Fig. 4E View FIGURE 4 ) 5.0 times longer than basal width, distally rounded, non-setose, basal endite bilobed, lobes subequal, short, rounded, sparsely setose, upper lobe with 4 slender simple setae, 5 on lower lobe, medial margin of coxa convex, non-setose, scaphognathite 2.6 times longer than wide, anterior lobe small, scarcely exceeding palp, as wide as long, posterior lobe long, slender and curved, 2.8 times longer than basal width.

First maxilliped ( Fig. 2D View FIGURE 2 ) with short tapering non-setiferous palp, basal endite about twice as long as broad, sparsely provided with long simple spiniform setae, exopod with small, broad sparsely setose caridean lobe, flagellum slender, with 4 plumose terminal setae, epipod small, bilobed.

Second maxilliped ( Fig. 2E View FIGURE 2 ) of normal form, dactylar segment 2.5 times longer than broad, medial margin straight, with long sparsely serrulate spiniform setae, flagellum slender with 4 plumose terminal setae, epipod lost in dissection.

Third maxilliped ( Fig. 2F View FIGURE 2 ) short, robust, ischiomerus completely fused to basis, combined segment about 5.3 times longer than central width, with 4 simple spiniform setae distally, penultimate segment of endopod about 0.4 of antepenultimate, 2.0 times longer than wide, with 3 simple spiniform setae medially, terminal segment 0.75 of penultimate segment length, with 3 groups of simple spiniform setae medially.

Male (vi): BPBM-S 1481, CL 1.05. Rostral dentition 3 / 0, with first pleopod ( Fig. 4L View FIGURE 4 ) without special features, endopod about 0.33 of exopod length, 2.6 times longer than central width, distally rounded with two short setae, one disto-medial seta, medial margin with two short curved spiniform setae proximally, without medial accessory lobe. Second pleopod ( Fig. 4M View FIGURE 4 ) with basipodite 2.0 times longer than central width, exopod 1.1 times basipodite length, 4.2 times longer than proximal with, tapering distally, endopod ( Fig. 4N View FIGURE 4 ) 0.7 of exopod length, appendix masculina obsolete, with single slender feebly setulose spiniform seta about 0.55 of endopod length at 0.4 of medial margin length, appendix interna about half length of medial spine.

Measurements (mm). Holotype female. Postorbital carapace length, 1.3; carapace and rostrum, 1.75; total body length (approx.), 5.5; major chela, 6.0; minor chela, 3.0; length of ovum, 0.5 mm.

Types. The ovigerous female (iii), collected on 19 June 1976, the only specimen which possesses both second pereiopods, is designated as the holotype ( BPBM-S 14815 ). The accessory teeth on the ambulatory dactyls were damaged in the process of examination. The specimen (iv) is selected as a paratype ( QM W28904). The remaining specimens are not in good condition .

Habitat. The specimens were obtained from dead heads of the scleractinian coral Pocillopora meandrina Dana collected from shallow water, about 3 m depth (Anne Fielding, pers. com.).

Systematic position. Readily distinguished from all Periclimenaeus species by the presence of a large articulated spine on the distoventral angle of the carpus of the ambulatory pereiopods. Periclimeneaeus devaneyi sp. nov. appears to most closely resemble Periclimenes minutus Holthuis 1952 from Banda Island, Indonesia, at a depth of 18–36 m, and Periclimenaeus jeancharcoti Bruce 1991 , first reported from New Caledonia at a depth of 375– 450 m. Both these species have spatulate fingers on the first pereiopod, the dactyl of the minor second pereiopod semicircular or suboval and strongly compressed with a convex cutting edge armed with strong teeth and the ambulatory dactyls compressed, short and stout, and biunguiculate with proximal spines on the corpus. Further information has recently been provided on P. minutus by Fransen (2006) showing that it closely resembles P. jeancharcoti with both species having the unguis of the ambulatory dactyl with a characteristic series of transverse corrugations at the proximal end of the dorsal margin. These are not present in P. devaneyi sp. nov. The ventral margin of the corpus bears minute denticles in P. jeancharcoti and P. minutus that are not present in P. devaneyi sp. nov. and the proximal ventral margin bears a cluster of small spinules in the former species and a single slender acute tooth in the latter.

Etymology. The species is named in honour of Dennis M. Devaney (1938–1983), Invertebrate Zoologist at the Bishop Museum, sadly lost at sea while collecting off Hawaii, in long overdue recognition of his contributions to knowledge of the marine fauna of the Hawai’ian region.

Remarks. Periclimenaeus devaneyi sp. nov. is remarkable, not only for the spines on the carpi of its ambulatory pereiopods, unique in the genus Periclimenaeus (and also in the Pontoniinae ), but also for its particularly small size, with adult females having a post-orbital carapace length of only 1.0– 1.5 mm. The specimens are presumed to be only indirectly associated with the Pocillopora coral and are most likely to have been associated with an encrusting sponge or ascidian hosts.

The types of P.minutus ( Figs. 6A–E View FIGURE 6 ) have been further re-examined. The male specimen, CL 2.5, still has both second pereiopods attached. The ovigerous female, dissected, lacks the minor second pereiopod. The major chela ( Fig. 6A View FIGURE 6 ) is massive, about 2.2 times the CL, the dactylus is very robust and distally thickened with a blunt tip. The proximal part of the cutting edge bears a large molar process and the distal part is sharp with minute acute denticulations (abraded distally). The fixed finger is stout and distally blunt, with a large proximal fossa. The distal cutting edge is bluntly rounded with several small rounded submarginal tubercles laterally. The minor chela ( Fig. 6B View FIGURE 6 ) is about 0.57 of the major palm length, with strongly compressed fingers. The dactylus ( Fig. 6D View FIGURE 6 ) is laminar, oval, about twice as long as maximum depth, dorsal and ventral margins similarly convex, with small acute tip, ventral cutting edge mainly sharp, closing into longitudinal groove on fixed finger, distal three fourths with about 15 acute teeth, largest distally and diminishing completely proximally, proximal fourth thickened, unarmed. Fixed finger distally strongly hooked (with tip missing), cutting edge deeply grooved, each margin with an acute process proximally.

It may be noted that, of the reports of Periclimenaeus minutus from the Western Indian Ocean by ( Bruce, 1976, 1978), only that from Mbweni, Zanzibar, QM W28905, may be correct. This specimen ( Figs. 6F–L View FIGURE 6 ), a male, CL 1.85, dredged from 9.1 m, corresponds closely to the figures of the type specimen provided by Holthuis (1952: 134–137, figs 57–59) and Fransen (2006: 271, fig.11). The other specimens lack the characteristic ambulatory dactyls and are therefore not conspecific. The Zanzibar specimen however, differs slightly in several features and may represent a separate species. It has a slender rostrum, reaching to about the distal margin of the first segment of the antennular peduncle, dentition of 5/0. The first pereiopod chela ( Fig. 6F View FIGURE 6 ) has the fingers subequal to the palm length, broadly and deeply spatulate, distally rounded with bidentate tips ( Fig. 6G View FIGURE 6 ), cutting edges laminar, entire. The major second pereiopod is missing. The minor second pereiopod has the palm ( Fig. 6H View FIGURE 6 ) about 1.75 times longer than deep, dactyl ( Fig. 6I View FIGURE 6 ) more oval, about 1.7 times longer than deep, 0.44 of palm length, with 13 large teeth (including tip), largest distally, decreasing rapidly in size proximally (some damaged), teeth ( Fig. 6J View FIGURE 6 ) generally larger and broader. Third pereiopod with propodus ( Fig. 6K View FIGURE 6 ) about 3.0 times longer than maximal width, tapering distally, distoventral angle with 2 stout spines with smaller preterminal ventral spine, without further ventral spines, dactyl ( Fig. 6L View FIGURE 6 ) about 0.25 of propod length, unguis 0.33 of corpus length, unornamented, slightly curved, corpus 1.5 times longer than proximal depth, dorsal margin feebly convex, ventral margin with acute erect preterminal tooth distally, with 2 small robust articulated spinules proximally, intervening ventral margin near straight.