Paraspongicola pusillus de Saint Laurent & Cleva, 1981

Saito, Tomomi & Komai, Tomoyuki, 2008, A review of species of the genera Spongicola de Haan, 1844 and Paraspongicola de Saint Laurent & Cleva, 1981 (Crustacea, Decapoda, Stenopodidea, Spongicolidae), Zoosystema 30 (1), pp. 87-147 : 138-141

Paraspongicola pusillus de Saint Laurent & Cleva, 1981

( Fig. 35 ) Paraspongicola pusilla de Saint Laurent & Cleva, 1981: 181 , figs 14a-g, 15a-g [type locality: Philippines, 150- 159 m].— Saito & Takeda 2003: 120.

TYPE MATERIAL. — Holotype: MUSORSTOM 1, stn 18, Philippines, 13°56.3’N, 120°16.2’E, 150-159 m, 21.II.1976, ♂ 3.2 mm (MNHN-Na 2932). Examined. Paratype: same data as holotype, 1 ovig. ♀ 3.1 mm (MNHN-Na 2931). Examined.

DISTRIBUTION. — Known only from the Philippines, 150-159 m ( Figs 36 ; 39 ; Table 6).

HOST. — Unknown.

DESCRIPTION OF FEMALE

Rostrum ( Fig.35A ) 0.53 of carapace length, straight, narrow triangular in dorsal view, reaching midlength of antennal scale; dorsal margin straight, armed with 10 teeth, including 3 teeth posterior to orbital margin; ventral margin armed with 1 minute subdistal tooth; ventrolateral ridge sharp, unarmed, confluent with orbital margin. Carapace ( Fig. 35A ) smooth, with postrostral median ridge extending to base of postrostral submedian spine; postrostral submedian spine small; antennal spine acute; hepatic spine absent; 3 anterolateral spines forming single oblique row; anterolateral margin minutely denticulate; cervical groove rudimentary.

Sixth thoracic sternite ( Fig. 35B ) with slender, spiniform lobes, narrowly separated medially, each lateral margin unarmed. Seventh sternite with broad, rounded lobes, separated by very narrow median incision; lateral margins sinuous, unarmed. Eighth sternite with bluntly triangular lobe, each lobe directed anterolaterally.

First pleonal somite divided in two sections by distinct transverse carina, posterior section partially overhanging deeply depressed anterior section;ventral margin produced in blunt process; posteroventral margin of posterior section unarmed. Second somite smooth, lacking transverse carina; pleura rounded and unarmed on ventral margin.Third to fifth pleura rounded, unarmed or armed with 1-4 small teeth on anteroventral and posteroventral margins. Sixth somite slightly widened posteriorly, with 1 lateral spine on either side; pleuron armed with 1 minute tooth on anteroventral margin. Telson broadly triangular, 1.5 times longer than broad; dorsolateral carinae each with 4 spines; lateral margins each with shallow subproximal concavity, and armed with 1 small submarginal spine and row of 8 or 9 spines; posterolateral angles each with 1 spine; posterior margin rounded, with posteromedian spine.

Cornea lightly pigmented in preservative, corneal surface distinctly faceted; eyestalk broadened basally, armed with 4 or 5 dorsal and 4 mesial spines, proximolateral margin sharply carinate.

Antennular peduncle reaching midlength of antennal scale; first segment longer than distal two segments combined, ventrodistal angle with 1 spine; stylocerite acute, curved mesially. Antennal basicerite stout, with dorsolateral distal angle produced in bifid projection, unarmed on ventrolateral margin; antennal scale subsemicircular, about 2.9 times longer than wide, lateral margin slightly concave, armed with 5 teeth including terminal tooth, dorsal surface with 1 obsolete longitudinal ridge; carpocerite long, only slightly falling short of tip of antennal scale.

Third maxilliped overreaching antennal scale by length of dactylus; dactylus 0.7 of propodal length, tapering distally; propodus 0.8 of carpal length, with grooming apparatus on distolateral part of ventral surface; carpus 0.7 of meral length, ventrodistal margin slightly produced; merus somewhat twisted, 0.6 ischial length, with 2 small spine distolaterally; ischium with row of 9 dorsolateral spines, distalmost strongest, ventral margin with 1 distal spine. Exopod nearly reaching to proximal margin of merus. First pereopod overreaching antennal scale by length of chela and half of carpus; dactylus 0.4 of chela length; palm with grooming apparatus restricted to proximoventral portion; carpus 1.6 of chela length, with grooming apparatus ventrodistally; merus 0.7 of carpal length; ischium 0.7 of meral length. Second pereopod relatively robust, slightly longer than third pereopod, about 3.0 times longer than carapace, overreaching tip of antennal scale by length of chela and carpus; dactylus 0.4 of chela length; palm subconical; carpus 0.7 of palm length; merus 1.4 of carpal length, with row of acute teeth on ventrolateral margin; ischium 0.6 of meral length. Third pereopod overreaching antennal scale by length of chela and carpus; dactylus half of chela length, with a few small teeth on proximal 0.3 of dorsal margin; fixed finger serrated on ventral margin over entire length; palm broad, 1.2 times longer than wide, serrated on dorsal and ventral margins; carpus broadened distally, 1.2 times as long as wide, 0.4 of chela length, unarmed; merus 1.6 of carpal length, with strong spine at dorsodistal angle, lateral margin with row of small teeth, distalmost strongest, proximomesial angle with 2 spines; ischium 0.6 of meral length, with strong dorsodistal spine, and row of small teeth or denticles on ventral margin.

Fourth and fifth pereopods similar, former overreaching antennal scale by length of dactylus and propodus; dactylus 0.3 of propodal length, broad, 2.5 times longer than wide, triunguiculate with 2 acuminate unguis and triangular projection at ventrodistal angle of corpus; propodus about half of carpus; merus 0.8 of carpal length; ischium 0.8 of meral length, unarmed.

Uropod with stout protopod; exopod with 20 (left) or 22 (right) acute teeth on lateral margin, dorsal surface of exopod with 2 longitudinal carinae; endopod with 10 (left) or 14 (right) acute teeth on lateral margin, terminal tooth strongest.

Egg diamter 0.7-1.0 mm (MNHN-Na 2931) ( Table 5).

MALE CHARACTERISTICS

Rostrum 0.52 of carapace length; dorsal margin with 11 teeth. Sixth thoracic sternite ( Fig. 35C ) with pair of rounded, contiguous lobes; seventh sternite with subtriangular lobes, each lobe nearly perpendicular, ventrolateral and distomesial margins serrated; eighth sternite with small, perpendicular lobes, each lobe acuminate, ventral margin denticulate. First pleonal somite with acute, elongate ventral projection on posterior section of pleuron; pleura of second to sixth somite acutely pointed posteroventrally, with serrated ventral margins. Second pereopod more robust than that of female; dactylus 0.4 of chela length; palm subcylindrical; palm and carpus subequal in length to merus respectively; ischium 0.6 of meral length.

REMARKS

Paraspongicola pusillus is so far represented only by the type series, including the male holotype and female paratype. We provide here figures of selected parts, including the thoracic sternum,in order to supplement the original description. The eyestalk of P. pusillus appears characteristic in having a sharp proximolateral carina.Shape of the thoracic lobes seems to be different between P. pusillus and P.inflatus n. comb. The sternal lobes on the seventh somite in females are rounded in P. pusillus , whereas they are subacute with distinctly concave anteromesial margins in P. inflatus n. comb. The sternal lobes on the sixth somite in males are rounded in P. pusillus , but they are bifid, very slender projections in P. inflatus n. comb.

Figures

FIG. 35. — Paraspongicola pusillus de Saint Laurent & Cleva, 1981: A, B, paratype ♀ 3.1 mm, Philippines (MUSORSTOM 1, stn 18) (MNHN-Na 2931); C, holotype ♂ 3.2 mm, Philippines (MUSORSTOM 1, stn 18) (MNHN-Na 2932); A, anterior part of carapace and cephalic appendages,lateral view (right antennule missing;mesial face of left antennule is shown);B, C, coxae of third to fifth pereopods and thoracic prominences, ventral views. Scale bars: A, 1 mm; B, C, 0.5 mm.

FIG. 36. — Bathymetric ranges of species of the genera Spongicola de Haan, 1844 and Paraspongicola de Saint Laurent & Cleva, 1981.

FIG. 39. — Geographic ranges of Paraspongicola inflatus (de Saint Laurent & Cleva, 1981) n. comb. (□) and P. pusillus de Saint Laurent & Cleva, 1981 (●).