Paragiopagurus schnauzer, Lemaitre, 2006

Lemaitre, Rafael, 2006, Two new species of Parapaguridae (Crustacea, Decapoda, Anomura, Paguroidea) with subconical corneas, and new data on biology of some rare species, Zoosystema 28 (2), pp. 517-532 : 524-530

publication ID	https://doi.org/ 10.5281/zenodo.5755035
persistent identifier	https://treatment.plazi.org/id/570587BB-FFC8-F366-835F-9033FE828FB9
treatment provided by	Marcus
scientific name	Paragiopagurus schnauzer
status	sp. nov.

Treatment

Paragiopagurus schnauzer View in CoL n. sp. ( Figs 5-8 View FIG View FIG View FIG View FIG )

TYPE MATERIAL. — Holotype: New Caledonia. BIO- GEOCAL, stn CP 214, 22°43.09’S, 166°27.19’E, 1590- 1665 m, 9.IV.1987, ♂ 3.3 mm (MNHN-Pg 7615). GoogleMaps

Paratype: Loyalty Islands. HALIPRO 2, stn BT 105, 25°45’S, 162°50’E, 1200-1218 m, 27.XI.1996, 1 ♂ 3.2 mm (MNHN-Pg 6705).

ETYMOLOGY. — The honoree of this Zoosystema issue will be pleased to see her favorite Schnauzer dog breeds, the Standard and Giant, recognized in the naming of this new species. Many generations of these noble and loyal dogs have provided her with loving company and protection.

DISTRIBUTION. — So far known only from the New Caledonian region; 1200 to 1665 m.

DESCRIPTION

Gills quadriserial ( Fig. 5A View FIG ), deeply divided. Shield ( Fig. 5B View FIG ) distinctly longer than broad, weakly calcified medially; dorsal surface with few short rows of setae. Rostrum broadly subtriangular, reaching well in advance of lateral projections; with short middorsal ridge. Anterior margins of shield straight; lateral projections broadly rounded; anterolateral margins sloping; anteroventral margins unarmed. Anterodistal margin of branchiostegite rounded, unarmed, setose.

Ocular peduncles ( Fig. 5C View FIG ) stout, diminishing in width distally, somewhat inflated ventroproximally; with longitudinal row of long setae dorsally; ventroproximal surface weakly calcified. Corneas reduced, subconical, terminating bluntly or sharply. Ocular acicles subtriangular, each terminating in strong spine; separated basally by about basal width of one acicle.

Antennular peduncles exceeding distal margin of corneas by 0.66 to nearly full length of penultimate segment; segments with scattered setae. Ultimate segment about 1.5 times as long as penultimate. Basal segment with strong ventromesial spine; lateral face with distal subrectangular armed with

one spine, and strong spine proximally. Ventral flagellum with six articles.

Antennal peduncles ( Fig. 5E View FIG ) exceeding distal margin of corneas by 0.30 length of fifth segment. Fifth segment with row of mesial setae. Fourth segment lacking spine on dorsodistal margin. Third segment with strong ventromesial distal spine. Second segment with dorsodistal angle produced, terminating in strong spine. First segment with small spine on lateral face; ventromesial angle produced, with row of one to three small spines laterally. Antennal acicle exceeding distal margin of cornea by about half length of acicle, terminating in strong spine; mesial margin with long setae, and armed with four to eight spines. Flagellum slightly exceeding distal margin of palm of right cheliped; with numerous short and long setae <1-4 flagellar articles in length.

Mandible ( Fig. 6A View FIG ) with three-segmented palp; cutting edge calcified, with small corneous tooth medially; molar process with small corneous tooth medially. Maxillule ( Fig. 6B View FIG ) with external lobe of endopod slender, moderately developed, not recurved, internal lobe with long, terminal seta. Maxilla ( Fig. 6C View FIG ) with endopod slightly exceeding distal margin of scaphognathite. First maxilliped ( Fig. 6D View FIG ) with endopod exceeding exopod in distal extension. Second maxilliped ( Fig. 6E View FIG ) without distinguishing characters. Third maxilliped ( Fig. 6F View FIG ) slender, merus to dactyl each distinctly longer than broad, ischium about twice as long as broad; crista dentata with about 14 corneous-tipped teeth; coxa and basis each with mesial spine. Sternite of third maxillipeds with small spine on each side of midline. Epistomial spine straight, simple.

Chelipeds markedly dissimilar. Right cheliped ( Fig. 5 View FIG F-H) with at most moderately dense, mostly plumose setae on dorsal surfaces of carpus and chela. Fingers slightly curved ventromesially, terminating in small, blunt corneous claws; cutting edges each with row of small blunt, or broadly rounded, unequal calcareous teeth, and with distal row of small corneous teeth (often worn out on fixed finger). Dactyl set at strongly oblique angle to longitudinal axis of palm; mesial margin well defined by row of spines or tubercles; dorsomesial surface with small spines; ventromesial face not concave or weakly so. Fixed finger broad basally, with scattered small tubercles on dorsal surface, unarmed on ventral surface except for a few tufts of setae. Palm broadening distally, slightly broader than long; dorsolateral margin well defined by small spines at least on distal half; dorsomesial margin with irregular row of small spines, mesial face rounded. Carpus longer than broad; dorsal surface with few, widely separated small tubercles or spines; dorsodistal margin with row of small spines; mesial surface rounded, with few small tubercles, ventrolateral and ventromesial distal margins each with row of small blunt spines. Merus usually with row of small spines on dorsodistal margin; with ventromesial distal row of small spines. Ischium and coxa with ventrodistal row of setae.

Left cheliped ( Fig. 5I View FIG ) well calcified, reaching when fully extended to about distal 0.50-0.75 of mesial margin of palm of right cheliped; dorsal margins carpus and dorsomesial margin of palm with long setae, otherwise with scattered short setae. Fingers terminating in sharp corneous claws; dorsal and ventral surfaces unarmed except for tufts of setae; cutting edge of dactyl with row of closely-set small corneous teeth, cutting edge of fixed finger with small, rounded calcareous teeth. Dactyl about as long as mesial margin of palm. Palm dorsal surface usually with small median spine or tubercle proximally; dorsomesial margin with row of few low, setose tubercles. Carpus with strong dorsodistal spine. Ischium and merus with setae on dorsal and ventral margins. Coxa with ventromesial row of setae.

Ambulatory legs or second and third pereopods ( Fig. 7 View FIG A-D) similar from right to left except for slightly longer meri on right; when fully extended reaching to, or slightly exceeding distal margin of right cheliped by about 0.2 or less length of dactyls. Dactyl 1.8 to 2.1 times as long as propodus, broadly curved, terminating in sharp corneous claw; with dorsal and distomesial rows of long setae; ventromesial surface with row of four to six small, corneous spinules. Propodus and carpus each with dorsal row of setae. Carpus with small dorsodistal spine. Merus with dorsal and ventral rows of setae. Ischium and coxa with ventromesial row of setae. Anterior lobe of sternite XII (third pereopods, Fig. 8C, D View FIG ) subsemicircular, sparsely setose, lacking spine.

Fourth pereopod ( Fig. 8A View FIG ) subchelate; merus, carpus, and propodus with setae on dorsal and ventral margins. Dactyl subtriangular, terminating in sharp corneous claw; with ventrolateral row of small corneous spinules. Propodus longer than wide, rasp consisting of one row (at least distally) of ovate scales.

Fifth pereopod ( Fig. 8B View FIG ) semichelate. Propodal rasp extending slightly beyond mid-length of segment. Dactyl with row of small rounded scales on ventral surface (in lateral view), lacking subterminal corneous tooth on prehensile margin.

Uropods and telson symmetrical or nearly so ( Fig. 8E View FIG ). Telson with weak or obsolete transverse suture; dorsal surface with scattered short setae and often low, blister-like tubercles; lateral margins with long setae mostly on distal half; posterior margin separated by shallow, narrow U-shaped cleft, into rounded projections each armed with about eight to 10 corneous spines, some often ventrally curved.

Male first gonopod ( Fig. 8F View FIG ) with concave distal lobe; second gonopod ( Fig. 8G View FIG ) with or without rudimentary exopod, distal segment with row of short bristles on lateral margin medially, and long setae on distomesial face. Female unknown.

Coloration

Live coloration unknown.

HABITAT

Scaphopod shells.

REMARKS

This new species is unique among Paragiopagurus species in having reduced, subconical corneas. As previously mentioned, it is only superficially similar to Oncopagurus conicus n. sp., and in addition to differences in generic characters, the two differ markedly in gill shape, quadriserial ( Fig. 5A View FIG ) in P. schnauzer n. sp., biserial ( Fig. 1A View FIG ) in O. conicus n. sp.; length of ocular peduncles relative to the shield, less than 0.50 shield length in P. schnauzer n. sp., more than 0.50 shield length in O. conicus n. sp.; and distal extension of the antennal acicles relative to the ocular peduncles, exceeding distal margins of corneas by about 0.50 length of the acicle in P. schnauzer n. sp., not exceeding distal margins of the corneas in O. conicus n. sp.

INTERESTING NEW MATERIAL AND MISNOMERS IN THE FAMILY

Typhlopagurus foresti de Saint Laurent, 1972 View in CoL ( Fig. 9 View FIG A-C)

Typhlopagurus foresti de Saint Laurent, 1972: 118 View in CoL , figs 26-29 (type locality: Borneo, 4°19’54’’N, 118°58’38’’E, 1630 m).

TYPE MATERIAL. — Holotype: Borneo. Albatross, stn 5582, 4°19’54’’N, 118°58’38’’E, 1630 m, 26.IX.1909, ♂ 3.6 m ( USNM 168313 About USNM ). GoogleMaps

Paratypes: same stn data as holotype, 2 ♀♀ 2.0, 2.3 mm ( USNM 168314).

OTHER MATERIAL EXAMINED. — Solomon Islands. SALOMON 1, stn CP 1781, 8°31.2’S, 160°37.7’E, 1036-1138 m, 29.IX.2001, 1 ♂ 3.7 mm, 2 ♀♀ 1.7, 1.8 mm, 3 ovig. ♀♀ 2.9-3.1 mm ( USNM 1084207 About USNM ; ex GoogleMaps

MNHN-Pg 6706); 12 ♂♂ 3.4-4.4 mm, 2 ovig. ♀♀ 2.4, 2.5 mm (MNHN-Pg 6707); stn DW 1853, 9°46.5’S, 160°52.9’E, 222-240 m, 7.X.2001, 3 ♂♂ 2.5-4.5 mm (MNHN-Pg 6708).

DISTRIBUTION. — Off northeastern Borneo, and now Solomon Islands; 222-1620 m.

REMARKS

De Saint Laurent (1972) erroneously cited the Philippines as the locality for Albatross stn 5582, the type locality. Actually, this station is off northeastern Borneo, south of Darvel Bay, Sabah. Previously known from only the type locality at 1630 m depth, T. foresti has now been found in the Solomon Islands at 222 m.

This is a rare and morphologically unusual species, and thus it is of interest to document that compared to most other parapagurids, females of T. foresti carry large and relatively few eggs. One of the ovigerous females herein reported with a shield length 2.7 mm (MNHN-Pg 6706), was found with a full load of eggs, only 11 in total, and each about 1.3 mm in diameter.

All the new specimens of T. foresti clearly have pigmented corneas, although small and located ventrodistally on the peduncle, at the base of a large terminal spine ( Fig. 9 View FIG A-C). The corneas are not easily observed in dorsal view. It appears that the corneal pigmentation disappears in preservation over time, or perhaps pigmentation is often absent, and this might explain why de Saint Laurent (1972) considered this species to lack corneas. A reexamination of the type material has shown that indeed the types lack pigment in the corneas. However, in the types as well the additional material here reported, the corneas can be discerned by the presence of corneal cuticular facets.

The new material of T. foresti extends the horizontal range of this species considerably to the west on the western Pacific. The vertical range is extended upward to a depth of 222 m, or 1408 m shallower than previously known.