dcsimg

Description

provided by NMNH Antarctic Invertebrates

"Archasterope bulla, new species Figures 243, 244

HOLOTYPE—USNM 128964, gravid female, length 2.04. Valves and some appendages in alcohol, remaining appendages on slides.

TYPE-LOCALITY—Vema Cruise 17, station V-17-23.

ETYMOLOGY—The specific name is derived from the Latin "bulla" [ = bubble, knob, boss, seal, edict, ornament] and refers to the 4 processes or knobs on the posterior infold of each valve.

PARATYPES—USNM 128965, adult female; USNM 128966, juvenile (not dissected). Both paratypes from same sample as holotype.

ADDITIONAL SPECIMENS—USNM 1S8033, N-l male, length 1.78 mm, height 1.00 mm, from Eltanin Cruise 6, station 354.

DIAGNOSIS OF ADULT FEMALE—In lateral view, posterior of carapace more broadly rounded in ventral half; 4 short processes forming row on infold between list and posterior shell margin; length about 2.04-2.16 mm.

Mandible: Ventral margin of basale with 3 small triaenid bristles near base of endite; dorsal margin of basale with 4 or 5 midbristles.

Maxilla: Ventral margin of basale with 4 midbristles; dorsal margin of basale hirsute.

Sixth limb: Posteroventral margin of end joint with 16 bristles.

Lateral eyes: Absent.

DESCRIPTION OF ADULT FEMALE—Carapace elongate; posterior end more broadly rounded in ventral half in lateral view; both ventral and dorsal margins fairly linear.

Infold: About 60 bristles forming 1 or 2 rows just within and parallel to anterodorsal margin above incisur; about 20 minute bristles present between rows of longer bristles and list; about 25 bristles present on list and between list and incisur; about 50 bristles present below incisur and on anteroventral infold; single row of 20 bristles present along ventral infold to point opposite 1st hyaline spine of posterior list; posterior list with 24 or 25 hyaline spines posterior to about 32 or 33 bristles (7 or 8 long, remaining short); 4 short processes forming row between list and posterior shell margin; 7 to 9 bristles (2 to 4 long, remaining short) present between lowermost hyaline spine on list and lowermost process in area between list and posterior shell margin.

Size: USNM 128964, length 2.04 mm, height 1.17 mm; USNM 128965, length 2.16 mm, height 1.20 mm.

First antenna: 1st and 2nd joints extremely spinous; 2nd joint with 1 long dorsal and 1 short lateral bristle, both with spines; 3rd joint with 6 long spinous dorsal bristles and 1 short bare ventral bristle; 4th joint with 1 long dorsal bristle with short marginal spines and 2 short ventral bristles about same length as ventral margin of 5th joint, both bristles with short marginal spines; ventral margin of 4th joint with spines forming clusters; sensory bristle of 5th joint long with short proximal and 6 long terminal filaments; medial bristle of 6th joint with short marginal spines. Seventh joint: a-claw with minute flat teeth near middle of lateral surface; b-bristle with 5 filaments including stem; c-bristle with 6 filaments including stem. Eighth joint: d- and e-bristles bare, d-bristle about 60 percent length of e-bristle, and tapering to suaged tip; f-bristle almost at right angles to stem, with 5 spinous filaments including stem; g-bristle with 7 filaments including stem.

Second antenna: Protopodite with short medial bristle and slender spines along ventral and dorsal margin and medial surface. Endopodite 3-jointed with long terminal bristle.

Exopodite: 1st joint elongate with hairs forming clusters along distal inner margin; joints 3 to 8 with short spines forming row along distal margin; bristle of 2nd joint reaching 9th joint and with numerous slender spines or hairs along ventral margins; bristles of joints 3 to 8 with natatory hairs; bristles of joints 3 to 5 with few stout proximal ventral spines; 9th joint with 4 bristles, 2 stout with natatory hairs, 2 short with short marginal spines; lateral spine with digitate tip present on 9th joint.

Mandible: Coxale with small bristle at base of endite; ventral margin of dorsal branch of coxale endite with 5 or 6 angular and rounded teeth and short main spine; dorsal bristle proximal to tip of endite with short marginal spines; ventral branch of coxale endite with spines forming 4 or 5 oblique rows and a pointed tip with 2 backward-pointing spines. Basale: endite with 4 spinous terminal bristles, 2 triaenid bristles with 4 and 8 pairs of marginal spines excluding terminal pair, 2 dwarf bristles and small glandular peg; 3rd smaller triaenid bristle with 6 spines (2 on one side, 4 on other or 3 pairs) excluding distal pair present near base of endite proximal to U-shaped sclerotized process; dorsal margin of basale with 2 long terminal bristles with short marginal spines and 5 short spinous midbristles on left limb and 4 on right. Exopodite about one half length of dorsal margin of 1st endopodite joint, with hirsute rounded tip and 2 short subterminal bristles. Endopodite: 1st joint with 3 long spinous bristles; medial and lateral surfaces of 2nd joint with short spines forming clusters; ventral margin with 3 long stout terminal bristles with short marginal spines; dorsal margin with 1 or 2 spinous proximal bristles and stout spinous a-, b-, c-, and d-bristles; 1 long spinous bristle present between b- and c-bristles; 3 spinous medial cleaning bristles forming oblique row between b- and c-bristles; 5 or 6 spinous medial cleaning bristles forming oblique row present between c- and d-bristles; 1 long stout spinous lateral bristle present between c- and d-bristles; 1 long stout spinous medial bristle present distal to base of d-bristle; 3rd joint with short pointed dorsal claw with minute teeth near middle, 3 long spinous clawlike bristles, and 2 slender spinous bristles.

Maxilla: Epipodial appendage short hirsute. Enditc 1 with 1 short and 3 long spinous bristles; endite II with 3 long bristles. Basale hirsute; 1 lateral and 1 bare medial bristle present near base of epipodite; dorsal margin with 3 short bare distal bristles; ventral margin with 4 bare midbristles, 1 short distal bristle and 1 long spinous terminal bristle. Endopodite: 1st joint with 1 short bare middorsal bristle and 1 long spinous 6-bristle; end joint with spinous bristle slightly longer than 6-bristle.

Fifth limb: Epipodial appendage with about 64 bristles. Comb with 1 long stout spinous exopodial bristle and 4 slender bristles near ventral margin distal to base of stout bristle (2 thin bristles may be close to base of stout bristle but not seen with certainty).

Sixth limb: Anterior margin with 1 upper and 1 lower bristle; anteroventral corner with 3 or 4 bristles plus 1 on margin of lateral flap; posteroventral margin with 16 bristles; limb hirsute.

Seventh limb: Each limb with 14 bristles, 8 proximal (4 + 4), 6 terminal (3 + 3), each with 3 or 4 bells; opposing terminal combs with about 14 opposing teeth.

Furca: Each lamella with 9 claws; last 2 or 3 claws bristlelike, straight or bent backward; remaining claws strongly curved, spines present on both concave and convex margins.

Medial eye and rod-shaped organ: Medial eye large with few hairs along dorsal margin; rod-shaped organ broadening proximally. With restriction near middle, tip rounded.

Lateral eye: Absent.

Upper lip: Central part with small anterior spines; each anterolateral lobe with 2 anterior spines, 1 small and 1 large; hirsute lateral flap present on each side of mouth; all lobes hirsute.

Posterior: Dorsal process thumblike with short and long spines (process bent backward on holotype).

Eggs: USNM 128964 with 11 eggs in marsupium.

COMPARISONS—The only species previously assigned to this genus is Archasterope dentata Poulsen, 1965. A. bulla differs from A. dentala in having 4 processes on the posterior infold of each valve and in not having lateral eyes.

REMARKS—USNM 138033, a male (N-l) also without lateral eyes.

DISTRIBUTION—This species was collected on the bottom at one locality in the Magellanic subregion at 279 m depth. It was also collected just outside the Magellanic subregion in a midwater trawl fished at a depth of 1812-2145 m at a station where the bottom depth was 3880-4118 m." (Kornicker 1975, p.384-388)

Habitat

provided by World Register of Marine Species
BENTHIC

Reference

6. Cordeiro, N. and Githiru, M. (2000) Conservation evaluation for birds of Brachylaena woodland and mixed dry forest in northeast Tanzania. Bird Conservation International, 10: 47 - 65.

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Danis, Bruno, B.