Diogenes patae, Asakura & Godwin, 2006

Asakura, Akira & Godwin, Scott, 2006, Diogenes patae n. sp., a new species of hermit crab (Crustacea, Decapoda, Anomura, Diogenidae) from American Samoa, Zoosystema 28 (2), pp. 457-463 : 458-463

publication ID

https://doi.org/ 10.5281/zenodo.5402845

persistent identifier

https://treatment.plazi.org/id/BF793B72-FFBC-DD59-6E17-FE64FE5AF94C

treatment provided by

Marcus

scientific name

Diogenes patae
status

sp. nov.

Diogenes patae View in CoL n. sp.

( Figs 1-3 View FIG View FIG View FIG )

HOLOTYPE. — American Samoa, Polynesia. SW side of Tau Island at Si‘ufa‘alele Point, Manua Islands , cruise TC0201, RV Townsend Cromwell, 14°14.824’S, 169°25.127’W, 15 m, scuba, carbonate pavement with low-growing corals, 11.II.2002, coll. Scott Godwin, ♀ SL 1.6 mm (BPBM-S-12268). GoogleMaps

ETYMOLOGY. — This new species is named in honour of Dr Patsy McLaughlin. The specific name uses “Pat”, the short and collegial version of the honoree’s first name, which she prefers. Pat is truly a great carcinologist who has made what will be longstanding contributions to crustacean biology, especially hermit crab taxonomy. The first author has benefited from her generous help, advice and encouragement in his hermit crab studies.

COMPARATIVE MATERIAL EXAMINED. — Diogenes pallescens : Funafuti, Ellice Islands, coll. G. Hedley, syntypes, 3 ♂♂, 4 ♀♀ SL 1.8-2.6 mm (AM G1402). — Vietnam, baie de Cauda, 11.IX.1953, coll. R. Serène, 1 ♂ SL 2.3 mm (MNHN-Pg 1502) (lectotype of Diogenes serenei ). — Maldives, Mahlos, coll. S. Gardiner, 2 ♂♂ SL 1.7-1.8 mm (MZCU) (syntypes of Diogenes gardineri ). Diogenes leptocerus : Vietnam, embouchure du Cuobe, 14.IV.1954, syntype, 1 ♂ SL 2.0 mm (MNHN-Pg 1416).

Diogenes tumidus : Indonesia, Sorong , Irian (= New Guinea), holotype, ♂ SL 2.4 mm (MNHN-Pg 5061). — Indonesia, XI.1991, 6 ♂♂ SL 1.4-2.3 mm ; 3 ♀♀ SL 1.3-1.4 mm (MNHN-Pg 5085).

Diogenes spinicarpus : Indonesia, TanjungTiram , Amboine, holotype, ♂ SL 1.8 mm (MNHN-Pg 5071) ; paratype, ♀ SL 1.8 mm (MNHN-Pg 7638). — Indonesia, Marsegu , Ceram, 16.IX.1993, 1 ♂ SL 2.0 mm (MNHN-Pg 7639) .

Diogenes biramus : Australia, Northern Territory, Coral Bay near headland, Port Essington, 4 m, 12.VIII.1986, holotype, ♂ SL 3.1 mm (WAM 156-87). — Australia, Beagle Reef, Kimberleys, 4-12 m, 24.VIII.1991, coll. Gary J. Morgan, 1 ♀ SL 2.5 mm, (WAM 173-91).

Diogenes capricorneus : Australia, Queensland, Coral sand, Masthead Island, 23°32’S, 151°44’E, coll. F. E. Grant, 1904, holotype, ♀ SL 2.5 mm (AM G5626).

DISTRIBUTION. — Known only from the type locality. DESCRIPTION

Shield ( Fig. 1A View FIG ) as long as broad; anterior margin between rostral lobe and lateral projections shallowly concave; anterolateral margins rounded, with spine on right anterolateral margin; lateral margins slightly convex, with three (left) or two (right) strong spines; dorsal surface flat, with scattered setae; rostral lobe obsolete; lateral projections blunt. Intercalary rostral process ( Fig. 1B View FIG ) bifid distally.

Posterior carapace with posterolateral plates very small, well calcified, unarmed.

Ocular peduncles (including corneas) ( Fig. 1A View FIG ) 0.8 length of shield, slightly inflated distally. Corneas ( Fig. 1A View FIG ) slightly dilated. Ocular acicles ( Fig. 1C, D View FIG ) with four spines distally.

Antennular peduncles ( Fig. 1A View FIG ) with ultimate segments slightly exceeding half length of ocular peduncles when fully extended; ultimate, penultimate and basal segments unarmed.

Antennal peduncles ( Fig. 1A, E, F View FIG ) short, with fifth segments at most reaching half length of ocular peduncles when fully extended. Fifth and fourth segments unarmed; third segment with ventrodistal angle produced; second segment with dorsolateral angle bearing strong spine and, on left, with small spine mesiad to it, dorsomesial distal angle with three spines; first segment unarmed. Antennal acicles short, each with three (left) or five (right) spines distally. Antennal flagella ( Fig. 1A View FIG ) short, 0.8 length of shield; articles each with few short setae distally.

Third maxilliped ( Fig. 1G View FIG ) with merus bearing large spine dorsally; ischium without crista dentata; basis unarmed.

Left cheliped ( Fig. 2 View FIG A-C) stout, with very dense, long setae obscuring armature on outer faces of dactyl, palm, carpus and merus. Dactyl and fixed finger each terminating in calcareous claw; cutting edges with several calcareous teeth; dactyl with upper surface bearing row of spines. Palm with upper face bearing row of spines and two additional spines distally. Carpus with upper face bearing one large and two small spines; distal margin of outer face with four spines on upper half and distal margin of inner face with one spine. Merus with two spines on distomesial angle and four large spines on ventromesial margin. Ischium unarmed.

Right cheliped slender ( Fig. 1H, I View FIG ), moderately setose. Dactyl and fixed finger each terminating in calcareous claw; dactyl with row of spines on outer margin of upper face. Palm with many spines on outer and lower faces.Carpus with upper face bearing double row of three strong spines and one strong distal spine; additional two spines present on outer face. Merus with ventrolateral margin bearing row of five strong spines distally; ventromesial margin with two subdistal spines. Ischium unarmed.

Second pereopods with left ( Fig. 2 View FIG D-G) bearing very dense, long setae obscuring armature on entire lateral faces of dactyl, propodus and carpus, and distolateral face of merus; right ( Fig. 3 View FIG A-C) with same surface moderately setose. Dactyls 0.9 length of propodi, each terminating in sharp, semi-transparent claw. Propodi 2.0-2.2 length of carpi, each with three small spines on distal margin of mesial face ( Figs 2E View FIG ; 3B View FIG ). Carpi 0.7 length of meri; each with sharp dorsodistal spine ( Figs 2F View FIG ; 3A View FIG ), and, on left, additional two sharp spines on mesial face dorsally (not shown in figure); lateral faces each with four (left, Fig. 2F View FIG ) or three (right, Fig. 3A View FIG ) spines. Meri each with four (left, Fig. 2G View FIG ) or two (right, Fig. 3A View FIG ) sharp spines on ventrolateral margin, and, on right, two additional sharp spines on ventromesial margin ( Fig. 3C View FIG ).

Third pereopods with left ( Fig. 3 View FIG D-G) bearing very dense, long setae obscuring armature on lateral faces of dactyl, propodus, carpus and merus; right ( Fig. 3H, I View FIG ) with same surface moderately setose. Dactyls 1.0-1.1 length of propodi, each terminating in sharp, semi-transparent claw. Propodi 1.7- 2.0 length of carpi, each with three small spines on distal margin of mesial face ( Fig. 3E, I View FIG ), and, on right, two strong spines on lateral face dorsally ( Fig. 3H View FIG ). Carpi 0.7-0.8 length of meri; each with sharp dorsodistal spine and, on left, additional one sharp spine in front of proximal margin of dorsal surface ( Fig. 3F View FIG ); three additional spines present on lateral face of right ( Fig. 3H View FIG ). Meri with lateral faces each bearing four (left, Fig. 3G View FIG ) or five (right, Fig. 3H View FIG ) spines ventrally.

Sternite X ( Fig. 1J View FIG ) (chelipeds) flat; sternites XI (second pereopods) and anterior lobe of sternite XII (third pereopods) subrectangular, very broad and flat.

Fourth pereopods with dactyl terminating in corneous claw; propodal rasp well developed; carpus with sharp dorsodistal spine.

Fifth pereopods chelate.

Abdomen dextrally twisted. Female with unpaired, unequally biramous, left 2-5 pleopods. Male unknown.

Uropods asymmetrical, left larger than right; endopodal and exopodal rasps well developed.

Telson ( Fig.1K View FIG ) asymmetrical, with posterior margin bearing sharp spines, median cleft obsolete.

Colour in life

Unknown.

REMARKS

The new species has very dense setation on the left cheliped and the left second and third pereopods. Such setation is not found on the right counterparts of these appendages. No such asymmetrical pattern of setation has been found in other species in the group. Generally the species in the group are not so setose except for D. tumidus , which has very dense plumose setae on the chelipeds and the ambulatory pereopods. However, the density of setation on the pereopods of D. tumidus is similar from left to right.

Presence of many spines on the lateral faces of the ambulatory pereopods is also characteristic to the new species, in particular on the second pereopod carpi.

The body of the new species is flattened, including the nearly flat dorsal surface of the shield and the flat and very broad sternites XI and XII. This appearance is quite similar to Clibanarius eurysternus Hilgendorf, 1879 , which is specifically adapted to living in Conus shells that have very narrow shell apertures and inner spaces. Unfortunately, the shell species used by the new species is unknown. In other species in the group, the shield is more or less vaulted.

In conclusion, the new species is easily distinguished from all other species in the group by the asymmetrical setation on the chelipeds and ambulatory pereopods, presence of strong spines on the lateral faces of the second pereopod carpi, and the dorsoventrally flattened body.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Diogenidae

Genus

Diogenes

Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF