Squillalbunea, BOYKO, 2002

BOYKO, CHRISTOPHER B., 2002, A Worldwide Revision Of The Recent And Fossil Sand Crabs Of The Albuneidae Stimpson And Blepharipodidae, New Family (Crustacea: Decapoda: Anomura: Hippoidea), Bulletin of the American Museum of Natural History 2002 (272), pp. 1-396 : 214-221

SQUILLALBUNEA , new genus

Paralbunea Serène, 1979: 97–98 (part). – Calado, 1995: 239–240 (part). – Boyko and Harvey, 1999: 380, 402 (key) (part) (not Paralbunea Serène, 1977 ).

Albunea: Coêlho and Calado, 1987: 41 (part) (not Albunea Weber, 1795 ).

DIAGNOSIS: Carapace wider than long, front narrow; anterior margin rugose but unarmed; carapace covered in strongly setose grooves; hepatic anterolateral spine absent; branchiostegite armed. Rostrum present, short. Distal peduncular segments flattened, shorter than anterolateral lobes, weakly indented mesially with mesial reduced corneas. Antennular segment I unarmed; dorsal flagellum with 46–57 articles, ventral flagellum with 3–7 articles. Antennal segment I unarmed; flagellum with 6–8 articles. Maxilliped III carpal projection short; weak crista dentata present; exopod slender. Pereopod I dactylus with dorsal margin toothed; propodus cutting edge smooth; distodorsal carpal spine absent. Males with small coxal pore on pereopod III. Telson of male elongate, triangular, laterally concave, fully calcified. Telsons exhibiting strong sexual dimorphism.

DISTRIBUTION: Indonesia; Western Australia and Queensland, Australia; and the Marquises Islands.

TYPE SPECIES: Albunea mariellae Serène, 1973 , by monotypy.

ETYMOLOGY: This genus is named for the indented appearance of the distal peduncular segments of its type species which resemble those of stomatopod crustaceans of the genus Squilla Fabricius, 1787 . That name is combined with Albunea , the type genus of the family. The gender is feminine.

REMARKS: Albunea mariellae was questionably placed in the genus Paralbunea by Serène (1979), who admitted that he had no material of that species on hand to examine. Indeed, this species does not belong in Paralbunea and is, in fact, a transitional form between Paralbunea and Zygopa . It is the sister taxon to Zygopa and shares several key characters (male telson shape, dactyli shapes, rugose and numerous carapace grooves) with that genus. The genus is monotypic.

Squillalbunea mariellae ( Serène, 1973) ,

new combination

Figures 70 , 71

Albunea mariellae Serène, 1973: 261–262 , pl. 1*. – Haig, 1974: 451 (list). – Coêlho and Calado, 1987: table 1.

Albunea undescribed species, Haig, 1974: 447 (list).

Paralbunea mariellae: Serène, 1979: 97–98 , fig. 4*. – Calado, 1995: 255–256, pl. 78, fig. 4. – Boyko and Harvey, 1999: 400 (list), 402 (key).

MATERIAL EXAMINED: Indonesia: Sta. KR VI/H 3–10, north of Pulu Durowa, north of Nuhurowa, Kai Archipelago, 05°32̍S, 132°41̍E, 15–20 fms (= 27.4–36.6 m), June 11, 1970, coll. Mariel King Memorial Expedition: 1 Ƌ, 13.3 mm cl, paratype ( WAM 10788).

Australia: Western Australia: Sta. 03B02BT, northwest shelf, 19°56.8̍S, 117°53.5̍E, 44 m, June 25, 1983, coll. CSI­ RO: 3 Ƌ, 5.9–6.9 mm cl, 2 ♀, 5.5–7.4 mm cl ( QM W22288) ; Sta. 02B02BT, northwest shelf, 19°56.8̍S, 117°53.4̍E, 42 m, April 22, 1983, coll. CSIRO: 3 Ƌ, 7.5–21.0 mm cl, 2 ♀, 11.6–12.0 mm cl, 2 juveniles, 5.1–7.9 mm cl ( QM W22289) ; Queensland: Pandora Reef, Pandora Wreck Site , under metal sheeting, 18°49̍S, 146°26̍E, Dec. 10, 1984, coll. Queensland Museum: 1 ♀, 22.3 mm cl ( QM W15789) .

Marquises Islands: Sta. TH­I, Haul 1, off Tahuata Island, 45 fms (= 82.3 m), Sept. 28, 1967, coll. National Geographic Society– Smithsonian­Bishop Museum Marquesas Expedition: 1 Ƌ, 10.8 mm cl ( USNM 304310).

DIAGNOSIS: As for genus.

DESCRIPTION: Carapace (fig. 70A) wider than long. Anterior margin concave on either side of ocular sinus, becoming concave and oblique laterally, numerous small rounded tubercles on and lateral to concave region, ventral row of long plumose setae submarginally. Rostrum as small acute spine, reaching one­half across ocular plate. Ocular sinus smoothly concave and unarmed. Frontal region covered in small setose, convex, scabrous lines; setal field broad posteriorly, narrowing anteriorly, with narrow indistinct lateral elements and indistinct straight anterior margin. CG1 parallel to anterior margin of carapace, sinuous, indistinct, medial and curved lateral elements widely separated. Mesogastric region covered in setose, convex, scabrous lines, CG2 present but not recognizable in field of setose grooves; CG3 present but not distinct; CG4 long lateral elements distinct and extending to anterior curve of CG6, median elements present but indistinct. Hepatic region covered in setose, convex, scabrous lines, with long setose groove at median of lateral margin. Epibranchial region generally triangular, medial region covered in setose, convex, scabrous lines, posterolateral margin with numerous short rows of setae. Metagastric region covered in setose, convex, scabrous lines; CG5 present but indistinct; CG6 slightly crenulate, entire, united with CG7; CG7 oblique and scalloped, united with CG6. Cardiac region covered in setose, convex, scabrous lines; CG8 present but indistinct; CG9–11 present but indistinct; post­CG11 groove present but indistinct. Branchial region completely covered with numerous short, curved rows of setae. Posterior margin deeply and evenly convex, with submarginal groove reaching to lateral margin of posterior concavity. Branchiostegite with small anterior submarginal spine, anterior region with scattered short transverse lines ventral to linea anomurica, with many short rows of setae and covered with long plumose setae ventrally, posterior region membranous, with numerous irregular fragments and covered with long plumose setae.

Ocular plate (fig. 70B) irregularly cylindrical, with shallow and broad median indentation. Median peduncular segments not vis­ ible, likely fused with ocular plate. Distal peduncular segments as flattened, globular, mesially indented, ‘‘mitten­shaped’’ ovals with convex lateral and mesial margins, cornea visible in depression at midpoint of mesial margin (junction of ‘‘thumb’’ and ‘‘forefinger’’ of imaginary ‘‘mitten’’), mesial margins widely separated along entire length, distal margins with long simple setae, dorsal surfaces with scattered patches of long simple setae, ventral surfaces each with proximolateral patch of long simple setae.

Antennule (fig. 70C) with segment III narrow proximally, expanding distally to three times proximal width; plumose setae on dorsal and ventral margins and scattered on lateral surface, dorsal exopodal flagellum with 46–57 articles (n = 6), long plumose setae on dorsal and ventral margins, ventral endopodal flagellum short, with three to seven articles (n = 6), plumose setae on dorsal and ventral margins. Segment II medially inflated in dorsal view, plumose setae on ventral margins. Segment I longer than wide, unarmed, long plumose setae on dorsal and ventral margins and scattered on dorsal third of lateral surface and submarginally on distoventral surface.

Antenna (fig. 70D) with segment V approximately four times longer than wide, long plumose setae on dorsal margin, flagellum with six to eight articles (n = 6), long plumose setae on dorsal, ventral, and distal margins. Segment IV expanded distally, long plumose setae on dorsal and ventral margins and in ventral submarginal row, and simple setae on dorsolateral margin. Segment III with long plumose setae on dorsal and ventral margins; few scattered short simple setae on lateral surface. Segment II short, width subequal along length, dorsal margin rugose, plumose setae on margins and lateral surface, antennal acicle long, thin, reaching distal margin of segment IV, long plumose setae on dorsal margin. Segment I rounded proximally, flattened ventromesially, long plumose setae on margins and dorsolateral surface; lateral surface unarmed, without dorsolateral lobe.

Mandible (fig. 70E) incisor process with two teeth; cutting edge with one tooth. Palp three­segmented, with plumose setae on mar­ gins and short, thick, simple setae arising from bend in second segment.

Maxillule (fig. 70F) distal endite proximally narrow, widening to inflated distal end, with thick simple setae on distal margin and thin plumose setae on dorsal margin. Proximal endite with thick simple setae on distal margin and thin plumose setae on dorsodistal and medioventral margins. Endopodal external lobe truncate distally and curled under, notched proximally; internal lobe reduced with three thick setae at distolateral margin.

Maxilla (fig. 70G) exopod evenly rounded, with plumose setae along distal margin. Scaphognathite bluntly angled on posterior lobe, with plumose setae.

Maxilliped I (fig. 70H) epipod with short plumose setae on margins and scattered on distolateral surface. Endite tapered distally and subequal to first segment of exopod. Exopod with two segments; proximal segment narrow, margins parallel, with plumose setae; distal segment spatulate, nearly one­half longer than wide, broadest medially, margins and distal three­fourths of lateral surface with long plumose setae. Endopod flattened and elongate, reaching nearly to distal end of proximal exopodal segment, with plumose setae on surface, thick simple setae on mesial margin.

Maxilliped II (fig. 70I) dactylus evenly rounded, length equal to width, with thick simple setae on distal margin and thin simple setae on medial distolateral surface. Propodus 1.5 times wider than long, with plumose setae on dorsal margin and long simple setae on dorsodistal and ventrodistal margins. Carpus not strongly produced dorsodistally, approximately two times longer than wide, with long simple setae on dorsal margin, dorsodistal and ventrodistal margins, and scattered on lateral surface. Merus nearly three times longer than wide, margins parallel, with long simple setae on dorsal and ventral margins and scattered on lateral surface, plumose setae on dorsolateral margin. Basis­ischium incompletely fused, with plumose setae on margins. Exopod one­third longer than merus, flagellum with one elongate article.

Maxilliped III (fig. 70J) dactylus rounded at tip, long plumose setae on margins and distal mediolateral surface. Propodus with longitudinal median row of plumose setae on lateral surface, dorsal and ventrodistal margins with plumose setae. Carpus strongly produced onto propodus and reaching to onehalf of length of propodus, lateral surface with longitudinal row of plumose setae medially and ventral submarginally; plumose setae on dorsal margin. Merus unarmed, slightly distally inflated, plumose setae on margins and scattered in patches on surface. Basis incompletely fused with ischium, with short plumose setae on margin; weak crista dentata of three or four very small rounded teeth. Exopod two­segmented, proximal segment small, distal segment styliform, tapering, approximately three­fourths length of merus, plumose setae on margins and surface; flagellum absent.

Pereopod I (fig. 71A) dactylus curved and tapering; lateral and mesial surfaces smooth; proximal half of dorsal margin with low tubercles, entire margin with long plumose and short simple setae, short simple setae on ventral margin. Propodal lateral surface with numerous short, transverse rows of setose rugae; dorsal margin rugose but unarmed; ventral margin distally produced into acute spine; cutting edge lacking teeth, lined with long plumose setae; dorsal, distal, and ventral margins with long setae. Carpus with dorsodistal angle rugose and scabrous, terminating in rounded tip; dorsal and distal margins with short plumose setae; lateral surface with distal rugose area, numerous transverse, setose ridges on lateral surface and in submarginal row distoventrally; mesial surface smooth, with one long subdorsal, one medial, and one short subventral row of long plumose setae. Merus unarmed; lateral surface with scattered transverse rows of long plumose setae, dorsal margin with long plumose setae; proximal fourth of mesial surface decalcified, smooth and without setae. Basis­ischium incompletely fused, unarmed. Coxa unarmed.

Pereopod II (fig. 71B) dactylus smooth; base to heel slightly convex, heel with smoothly rounded low spur, heel to tip broadly indented and wide, tip acute, tip to base broadly convex; lateral surface smooth, three small tufts of short setae on base of heel, several widely spaced submarginal tufts of short setae dorsodistally; mesial surface smooth, ventral margin with long plumose setae, dorsal margin with row of long plumose setae from junction with propodus to median of heel. Propodal dorsal surface smooth, ventral margin proximally inflated and rounded; oblique row of long plumose setae on distal margin of lateral surface; distal and ventral margins with long plumose setae; dorsolateral surface as narrow, oblique, flattened shelf, short setae on dorsal margin and long plumose setae on ventral margin; mesial surface with elevated, curved, setose ridge from ventral junction with dactylus almost to ventral proximal junction with carpus. Carpus produced one­third over propodus, gently rounded dorsally with rounded distoventral angle; proximal fivesixths of lateral surface nearly smooth, with irregular, short interrupted row of rugae medially and submarginal elevated ridge ventrally, rugae and ridge with long plumose setae, distal sixth of lateral surface rugose, with mat of short thick simple setae, dorsal and distoventral margins with long plumose setae; mesial surface smooth, distal and ventral rows of long plumose setae, two dorsal submarginal interrupted rows of long plumose setae. Merus with medial decalcified area on lateral surface, long plumose setae on dorsodistal and ventral margins; mesial surface nearly smooth, with many short rows of long plumose setae. Basis­ischium incompletely fused and unarmed. Coxa unarmed.

Pereopod III (fig. 71C) dactylus with base to heel almost straight, heel rounded and not produced, heel to indent convex, indent broadly concave, tip acute, tip to base smoothly convex; lateral surface smooth, base of heel and dorsodistal margin with tufts of short setae, ventromesial margin with long plumose setae, dorsal margin with short simple and plumose setae; mesial surface smooth, row of plumose setae from junction with propodus to heel, dorsal submarginal row of short simple setae on distal threefourths of blade. Propodus weakly inflated; lateral surface smooth, long plumose setae distally, simple setae on margins, long plumose setae on ventral margin, dorsolateral surface narrow, oblique, flattened, with mat of short simple setae; mesial surface with few long setae in oblique medial row and on distoventral angle. Carpus produced dorsodistally, inflated, reaching one­third length of propodus, broadly rounded, dorsolateral margin unarmed; lateral surface slightly rugose dorsodistally, with mat of short simple setae covering distal third of surface and short sim­ ple setae scattered on dorsal half of lateral surface proximal to setose mat; fully calcified, with two long rows of short setae medially; mesial surface smooth, long plumose setae on and near distoventral margin. Merus smooth, margins unarmed, distodorsal and ventral margins with long plumose setae; lateral surface with decalcified area distally and few scattered long setae on proximal third; mesial surface smooth, with few scattered setae. Basis­ischium incompletely fused and unarmed. Coxa unarmed. Female with large gonopore on median mesial surface of coxa, not opposing other gonopore, without surrounding setae; male with smaller but distinct pore.

Pereopod IV (fig. 71D) dactylus with base to tip convex, tip acute, tip to base broadly convex; lateral surface smooth, ventral margin with long plumose setae, dorsal margin with short and long simple setae; mesial surface with median decalcified area, demarcat­ ed ventrally by longitudinal elevated ridge with row of long plumose setae, setose punctae ventral to decalcified window. Propodus expanded dorsally and ventrally, ventral expansion exceeding ventral margin of dactylus, ventral margin with long plumose setae, dorsal expansion with row of long plumose setae dorsally and mat of short simple setae ventrally; lateral and mesial surfaces smooth, with few scattered long, plumose setae. Carpus not produced dorsodistally with mat of short simple setae on dorsal half of lateral surface; lateral and mesial surfaces smooth, mesial surface with distal and ventral row of long plumose setae and faintly medially decalcified area, dorsal margin with short simple and long plumose setae, ventral margin with few short plumose setae. Merus with scattered short transverse rows of setae on lateral surface, dorsal and ventral margins with long plumose setae; proximal fourth of mesial surface with large decalcified window. Basis­ischium incompletely fused and unarmed. Coxa unarmed.

Abdomen (fig. 71E) with somite I wider than long, widest posteriorly; dorsal surface with anterior margin convex, posterior margin concave, with submarginal elevated and curved row of short setae, small transverse decalcified submedial windows present. Somite II dorsal surface with submarginal transverse ridge anteriorly, row of setae at posterolateral angle, extending onto pleura posteromesially; pleura expanded and direct­ ed anterolaterally, anterior margin angled, posterior margin rounded, anterior and lateral margins with long plumose setae, posterior margin with short setae, posterior dorsal surface with two rows of short simple setae submarginally. Somite III similar to somite II, but narrower, shorter, small row of short thick setae on posterolateral angle; pleura thinner and shorter than on somite II, direct­ ed anterolaterally, with setae as in somite II except only one row of posterior submarginal setae present, anterolateral angle acute, dorsal surface obliquely flattened anterolaterally with short simple setae on lower margin. Somite IV similar to somite III, but thinner and shorter; pleura thinner and shorter than on somite III, directed slightly anterolaterally, dorsal surface obliquely flattened anterolaterally with setae as in somite III, margins with long plumose setae. Somite V subequal to somite IV, lateral margins with plumose setae; pleura absent. Somite VI subequal to somite V in width but longer, dorsal surface with four short transverse rows of setae laterad of midline anteriorly, lateral and posterior margins with long plumose setae; pleura absent.

Females with uniramous, paired pleopods on somites II–V, males lacking pleopods.

Telson of male (fig. 71F) triangular, proximolateral margins convex, with short simple setae on surface, tapering distally with concave lateral margins, rounded at tip, evenly calcified, margins with long plumose setae; median longitudinal groove extending along medial half with short simple setae along length of groove. Telson of female (fig. 71G) triangular, proximolateral margins convex, with short simple setae on surface, only slightly tapering distally with nearly straight lateral margins, distal tip smoothly rounded, with short setae along length of median groove; lateral margins with long simple setae.

DISTRIBUTION: Known from Indonesia; Western Australia and Queensland, Australia; and the Marquises Islands , in up to 82.3 m depth .

MAXIMUM SIZE: Males: 21.0 mm cl; females: 22.3 mm cl.

TYPE SPECIMENS: WAM 125–71 (holotype, lost), WAM 10788 (paratype, old no. 126– 71).

TYPE LOCALITY: North of Pulu Durowa, north of Nuhurowa, Kai Archipelago, Indonesia, 05°32̍S, 132°41̍E, 15–20 fms (= 27.4–36.6 m).

REMARKS: The holotype was lost in the mail en route to Brazil (Hewitt, personal commun.), and it is fortunate that so many additional specimens have subsequently been located. This is the first report of specimens of this species since the original description. Serène (1979) tentatively placed this species in his genus Paralbunea , but it is quite distinct from that genus. It appears to be an important transitional form between Zygopa and the rest of the Albuneinae . Although most closely related to Zygopa , this species cannot be included in that genus and is herein designated the type of a new genus, Squillalbunea .

Calado (1995) saw no material of this species and redescribed it based on the text and illustrations of Serène (1973).

The presence of this species is now confirmed in Western Australia ( Haig, 1974; Boyko and Harvey, 1999) and is reported for the first time from Queensland and the Marquises Islands. The total number of species of albuneids known from the Marquises Islands is now three (see Boyko, 2000a).

Figures

Fig. 70. Squillalbunea mariellae (Serène, 1973), n. comb.: A, ♀, 22.3 mm cl, QM W15789; B–J, Ƌ, 10.8 mm cl, USNM 304310. A. Carapace, branchiostegite, and ocular peduncles, dorsal view. B. Ocular peduncles, dorsal view. C. Left antennule, lateral view. D. Left antenna, lateral view. E. Left mandible, mesial view. F. Left maxillule, lateral view. G. Left maxilla, lateral view. H. Left maxilliped I, lateral view. I. Left maxilliped II, lateral view. J. Left maxilliped III, lateral view. Scale = 1.1 mm (B), 1.6 mm (E, F), 2.2 mm (I), 3.0 mm (C, D), 3.3 mm (G, H, J), and 7.2 mm (A).

Fig. 71. Squillalbunea mariellae (Serène, 1973), n. comb.: A–F, Ƌ, 10.8 mm cl, USNM 304310; G, ♀, 22.3 mm cl, QM W15789. A. Left pereopod I, lateral view. B. Left pereopod II, lateral view. C. Right pereopod III, lateral view. D. Left pereopod IV, lateral view. E. Abdominal somites I–VI, dorsal view. F. Telson of Ƌ, dorsal view. G. Telson of ♀, dorsal view. Scale = 2.2 mm (F), 3.3 mm (A–E), and 4.4 mm (G).