Stratiotes breviantennatus, Rahayu, Dwi Listyo, 2005

Rahayu, Dwi Listyo, 2005, Additions to the Indonesian fauna of the hermit crab genus Pseudopaguristes McLaughlin and a further division of the genus Paguristes Dana (Crustacea: Decapoda: Paguroidea: Diogenidae), Zootaxa 831, pp. 1-42 : 12-16

Stratiotes breviantennatus n. sp. ( Figs. 4 , 5 )

Material examined. Holotype: male, 9.0 mm, Snellius II, stn.104, north­east of Komodo Island, 08°25.3'S, 119°36.2'E, 140 –150 m, 20 Sept 1984 ( MZB).

Description. Biserial phyllobranchiae. Shield ( Fig. 4 a) longer than broad; lateral margins sloping, dorsal surface rugose, with low elevation on either side of midline and short transverse row of small spines and tuft of setae. Rostrum broadly triangular, distinctly overreaching lateral projections, terminating in acute spine obscured by dense setae. Lateral projections triangular, with acute marginal spine. Ocular peduncles slender, 0.6 length of shield; corneal diameter 0.2 of peduncular length; ocular acicles small, distinctly separated basally, terminating acutely, with moderately long, plumose setae. Antennular peduncles, when fully extended, reaching bases of corneas; basal segment with distal acute spine dorsomesially and dorsolaterally, and 1 median spine dorsolaterally. Antennal peduncles reaching nearly to or slightly overreaching half length of ocular peduncles; fifth segment unarmed; fourth segment with dorsodistal spine; third segment with ventromesial distal angle strongly produced terminating in strong spine; second segment with dorsolateral distal angle produced, terminating in prominent simple or bifid spine, subdistal spine frequently present on lateral margin, dorsomesial distal angle with strong spine; first segment unarmed. Antennal acicle reaching to or slightly beyond distal margin of ultimate peduncular segment, terminating in prominent bifid spine, mesial margin with strong proximal spine, lateral margin with 2 spines. Antennal flagellum 2.5 times shorter than carapace, consisting of about 17 articles, each article with short, sparse setae.

Basis of third maxilliped with 2 distoventral spines; ventral margin of ischium with distal spine; merus with 4 small spines on ventral margin.

Chelipeds ( Fig. 4 b, c) subequal, armature similar. Ischia each with row of minute spinules or granules on ventromesial margin. Meri each with 1 spine at dorsodistal margin, dorsal margin with 2 distal transverse rows of spines extending mesially and laterally; ventromesial margins each with row of strong spines and tuft of plumose setae; ventrolateral margins each with row of less prominent spines and dense plumose setae; mesial faces glabrous, lateral faces with scattered small tubercles. Carpi each with row of 4 conical spines on dorsomesial margin; dorsal surface with 2 irregular rows of spines, first row adjacent to dorsomesial margin, consisting of moderately small spines or tubercles, second row with more numerous and moderately larger spines; tuft of moderately dense setae on dorsal surface. Palms half length of carpi. Dorsomesial margins each with 3 strong, occasionally corneous­tipped spines; dorsal surfaces each with several irregular rows of large, occasionally corneous­tipped spines, becoming closely­spaced on fixed finger; ventral surfaces each with single row of large spines medially, not extending to fixed finger; cutting edge with small calcareous teeth, terminating in moderately large corneous claw. Dactyls approximately 3 times length of palms; each with row of large, corneous­tipped spines on dorsomesial margin; dorsal surface with rows of small to moderately large spines, one strong spine proximally; mesial surface with large corneous, widely­spaced spines and tufts of setae; cutting edge with small calcareous teeth, terminating in small corneous claw; no hiatus between dactyl and fixed finger. Tufts of dense setae on entire surface of palm, fixed finger and dactyl concealing spines and tubercles.

Left and right pereopods similar. Ischia of second pereopods ( Fig. 5 a, b) each with row of spinules on ventromesial margin. Meri each with row of small spines on ventrolateral margin, stronger row of spines on ventromesial margins. Carpi approximately 0.8 length of meri, each with dorsal row of 6 irregular, strong spines; lateral faces convex, each with longitudinal sulcus near dorsal margin accompanied by 2 distal spines. Propodi slightly longer than carpi, each with dorsal row of 8 irregular, moderately large spines, dorsodistal margin with small corneous spines; lateral surfaces convex, each with row of protuberances accompanied by tufts of setae near dorsal and ventral margins, row of tufts of shorter setae in midline; mesial surface adjacent to ventral margin with longitudinal row of clusters of 2 spines, each cluster with tuft of setae, low protuberance accompanied by long setae near dorsal margin; ventral margins each with denticles. Dactyls 1.4 length of propodi, dorsal margins each with row of corneous spines proximally; mesial surfaces each with row of small spiniform setae near dorsal and ventral margins; ventral margins each with row of small spiniform setae, stronger distally. Mesial and lateral faces of dactyls each with faint longitudinal sulcus proximally. All surfaces and particularly dorsal and ventral margins partially or completely obscured by long and dense plumose setae.

Third pereopod ( Fig. 5 c, d) with ischia unarmed. Meri each with row of very small spines or spinules on dorsal surface; ventromesial distal angle each with small spine, ventromesial and ventrolateral margins each with row of spines. Carpi slightly shorter than meri, each with small irregular spines on dorsal margins; lateral surfaces convex, each with longitudinal sulcus near dorsal margin. Propodi each with minutely spinulose dorsal and ventral surfaces; lateral faces with protuberances accompanied by long setae, shallow longitudinal sulcus accompanied by tufts of setae in midline; mesial surfaces each with 2 rows of corneous­ tipped spines: 1 row near ventral margin composed of clusters of 2–3 small corneous­tipped tubercles with tufts of setae on each cluster and 1 other row of simple spines near dorsal margin, concealed at least partially by dense setae. Dactyls almost 1.5 longer than propodi; dorsal margins each with row of minute spinules; mesial faces each with irregular rows of spiniform setae; lateral and mesial faces each with narrow longitudinal sulcus proximally; ventral margins each with spiniform setae. All surfaces and particularly dorsal and ventral margins, partially or completely obscured by long and dense plumose setae. Fourth pereopod (fig. 4e) with preungual process.

Male first pleopods ( Fig. 5 e, f) robust; inferior lamella obtusely triangular, distal margin with several rows of hook­like spines. External lobe elongate, tip curve, separated from internal lobe by deep narrow cleft; internal lobe broad. Female unknown.

Telson ( Fig. 4 d) with posterior lobes asymmetrical, separated by narrow cleft; right lobe smaller, terminal margins of left and right lobes with row of tiny spinules extending onto proximal half of lateral margins.

Etymology. The specific name is derived from Latin brevi, meaning short, and antennae, alluding to the short antennal peduncles.

Habitat. The single specimen was collected from substrate of calcareous block with sponges, epifaunal tunicates and scleractinians.

Distribution. Komodo Island, 140– 150 m.

Remarks. Stratiotes breviantennatus sp. nov. is easily distinguished from other species of the genus by the shape of the telson, which has row of small spinules almost the entire length of the terminal margins. The short and almost glabrous antennal flagella also separate this species from its congeners.

Figures

FIGURE 4. Stratiotes breviantennatus n. sp., holotype, male, 9.0 mm (MZB): a, shield and cephalic appendages, setae omitted; b, c, left cheliped, setae omitted; d, telson; e, right fourth pereopod, setae omitted (lateral view); b, dorsolateral view; c, mesial view. Scales equal 1 mm.

FIGURE 5. Stratiotes breviantennatus n. sp., holotype, male, 9.0 mm (MZB): a, b, right second pereopods, setae omitted; c, d, right third pereopods, setae partially omitted; e, f right first pleopod, setae omitted; a, c, lateral view; b, d, mesial view; e, external view; f, internal view. Scales equal 1 mm.