“Archasterope efficax Kornicker, new species
Figures 82-86
Archasterope species A, Kornicker, 1994, fig. 111g-k.
ETYMOLOGY.—From the Latin efficax (effectual, powerful).
HOLOTYPE.—NMV J37165, partly dissected ovigerous female in alcohol.
TYPE LOCALITY.—Slope 48, 41°57.50’S, 148°37.90'E, Tasmania, off Freycinet Peninsula; depth 400 m.
PARATYPES.—Slope 1: NMV J37167, 7 juveniles in alcohol. Slope 40: USNM 193983, ovigerous female on 2 slides and in alcohol; USNM 193984, 1 adult male on 2 slides and in alcohol. Slope 48: NMV J37166, 1 undissected juvenile male in alcohol.
DISTRIBUTION.—Slope 1,204 m. Slope 40,400 m. Slope 48, 400 m.
DESCRIPTION OF ADULT FEMALE.—
Carapace elongate with slightly convex ventral and dorsal margins and evenly rounded anterior and posterior margins; incisur ventral to midheight.
Infold: Anterior and anteroventral infold with numerous bristles; broad list of posterior infold with 21-24 broad transparent bristles with pores at bases, 24 long slender bristles, and about 86 minute bristles; posterior infold between broad list and posterior end of valve with 6 processes and about 40 bristles (bristles posterior to 5-7 broad transparent bristles at ventral end of posterior list longer).
Selvage: Fringed lamellar prolongation along ventral edge of incisur.
Vestment: Anterodorsal part of vestment proximal to infold with few rows of long hairs.
Central Adductor Muscle Attachments: Comprising 18 or 19 ovoid attachments just anterior to valve midlength and just ventral to valve midheight.
Carapace Size (length, height in mm): Slope 40: USNM 193983, 2.03, 1.21, height 60% of length. Slope 48: NMV J37165 (holotype), 2.13, 1.25, height 59% of length. Length range 2.03-2.13, height range 1.21-1.25; range of height as percent of length 59-60.
First Antenna: 1st joint with medial and lateral spines (Figure 82e). 2nd joint with ventral spines, proximal dorsal spines, medial and lateral spines near ventral margin, and 2 bristles (long dorsal bristle with long spines, short lateral bristle with broad distal 3rd bearing triaenid-type spines. 3rd joint with well-defined distal margin, small bare ventral bristle, and 6 dorsal bristles (2 single (proximal), then 2 almost adjacent, and 2 paired (distal); all dorsal bristles with long spines). 4th joint with concave dorsal margin and 3 bristles (1 long dorsal, 2 short ventral) with short spines. Sensory bristle of 5th joint with short proximal filament and 6 long terminal filaments. Medial bristle of 6th joint about 1/4 longer than a-bristle of 7th joint, with short marginal spines. 7th joint: a-bristle claw-like with indistinct dorsal spines; b-bristle slightly shorter than sensory bristle of 5th joint, with 4 long marginal filaments; c-bristle longer than sensory bristle of 5th joint, with 9 marginal filaments. 8th joint: d-and e-bristles well developed with blunt tips; d-bristle slenderer than e-bristle and about 3A of its length; f-bristle bent dorsally, about same length as c -bristle, with 5 marginal filaments; g-bristle slightly longer than c-bristle, with 6 marginal filaments.
Second Antenna: Protopodite with small distal medial bristle, distal spines on dorsal margin, medial spines on distal dorsal half, and row of few medial hairs near base of endopodite. Endopodite 3-jointed with terminal filament about twice length of stem. Exopodite: Bristle of 2nd joint reaching 9th joint, with numerous slender hair-like ventral spines (proximal spines shorter and stouter); bristle of joint 3 with ventral spines and natatory hairs; bristles of joints 4-8 with natatory hairs; 9th joint with 4 bristles (2 long with natatory hairs, 2 short with short slender spines); joint 4 with 2 or 3 minute basal spines; joints 5-8 with small basal spine (spine of 8th joint about 1/5 length of 9th joint); 9th joint with lateral spine about half length of joint; joints 2-8 with row of minute spines along distal edges.
Mandible: Coxale endite: With small bristle at base of ventral branch; ventral branch with spines forming 6 rows and with tip having 1 short stout spine and 1 longer slender spine; ventral margin of dorsal branch with 7 low nodes proximal to small main spine; edge between main spine and tip of branch with a spine similar to main spine but smaller, then row of smaller spines; tip of branch with small spines but no bristle; dorsal margin of dorsal branch with bristle (with few spines near base) set back from tip of branch (bristle broken on illustrated endite) and with serrations proximal to bristle; coxale proximal to endite and with long medial hairs. Basale endite with 4 spinous end bristles, glandular peg, 2 dwarf bristles, and 3 triaenid bristles with 10 or 11 paired spines excluding terminal pair. Basale: Ventral margin with short triaenid bristle (with 3 paired spines proximal to terminal pair) proximal to U-shaped boss; dorsal margin with long proximal hairs, 1 short bare bristle at midlength, and 2 long terminal bristles with short spines; lateral side with long proximal hairs near dorsal margin. Exopodite hirsute, about half length of dorsal margin of 1st endopodial joint, with 2 short subterminal bristles. 1st endopodial joint with 3 long ventral bristles (1 with short spines, 2 with long spines). 2nd endopodial joint: Dorsal margin with 2 short slender proximal bristles with short spines, stout spinous a-, b-, c-, and d-bristles (c -bristle with base broader than that of d-bristle), 1 long spinous lateral e-bristle between b- and c-bristles, 1 long spinous lateral f-bristle between c- and d-bristles, 1 long spinous medial g-bristle near base of d-bristle, and 8 cleaning bristles (3 between b- and c -bristles, 5 at base of c -bristle); ventral margin with 3 long spinous terminal bristles; medial surface with rows of spines. 3rd endopodial joint with stout dorsal claw with small ventral spines at midlength, and 5 bristles (1 medium, 4 long) with short marginal spines.
Maxilla: Epipodite with hirsute tip broken off on illustrated limb. Endite I with 4 bristles (1 short slender, 3 long stout spinous); endite II with 3 long stout spinous bristles; 1 or 2 indistinct minute spine-like bristles between endites but closer to endite II (barely visible at high magnification (xlOO objective, xl5 ocular)). Basale: Medial surface near dorsal margin with stout proximal bristle (broken off on both limbs of USNM 193983, but stump remaining on left limb shown in Figure 83c [in cited text]) and 1 short slender distal bristle; ventral margin with 9 or 10 slender bare medial bristles proximal to midlength of basale, 1 small distal bristle (base on lateral surface), and 1 long spinous terminal bristle; medial surface spinous; usual proximal lateral bristle not observed, possibly obscured. 1st endopodial joint with few distal spines, small bare alphabristle, and long beta-bristle with few short marginal spines. 2nd endopodial joint with terminal bristle (with few spines) reaching very slightly past tip of beta-bristle.
Fifth Limb: Lateral side of comb with stout spinous exopodial bristle reaching past end of comb, 2 short slender bristles just ventral to base of stout bristle, 2 pairs of bristles closer to ventral margin of comb, and 4 bristles almost on ventral margin.
Sixth Limb: Limb hirsute. Small medial bristle near proximal anterior comer. Anterior margin of right limb of USNM 193983 with 1 bristle at both upper and lower endite sutures, but left limb with bristle only at lower suture (the possibility that the bristle of the upper suture may have been pulled out is indicated by an indistinct empty socket, but the socket was not identified with certainty). Anteroventral corner with 3 small bristles. Posteroventral margin with 26 bristles (possibly 1 or 2 more were present on missing section of proximal posterior margin of illustrated limb.
Seventh Limb: Each limb with 12 bristles: 6 proximal (3 on each side) and 6 distal (3 on each side); each bristle with 3 or 4 bells. Terminus with opposing combs, each with about 11 spinous teeth of similar length.
Furca: Each lamella with 9 claws (posterior 2 bristle-like, recurved); claws 1-7 with teeth along posterior edge; claws 1-5 with distal hairs along anterior edge; small triangular segment posterior to lamellae with minute spines.
Bellonci Organ: Elongate with rounded tip.
Eyes: Medial eye unpigmented, bare. Lateral eye well developed, about same size as medial eye or slightly smaller, unpigmented, with 12 or 13 ommatidia.
Lips: Upper lip a hirsute lobe on each side of indented saddle; each lobe with 2 or 3 small spines. Lower lip a hirsute flap on each side of mouth.
Genitalia: Oval structure on each side of body anterior to furca.
Anterior of Body: Without anterior process.
Posterior of Body: Dorsal half hirsute; with short spinous thumb-like dorsal process.
Y-Sclerite: Typical for subfamily.
Eggs: Slope 40: USNM 193983 with 19 eggs in marsupium (lengths of 3 eggs (mm): 0.30, 0.31, 0.32). Slope 48: Holotype with 17 eggs in marsupium (length of typical egg 0.31 mm).
DESCRIPTION OF ADULT MALE.—Carapace with dorsal margin sloping posteriorly, and with low ridge extending from anteroventral corner to inner end of incisur; posterior end with vertical row of hair. Carapace larger and more elongate than that of adult female.
Infold: Not examined.
Carapace Size (length, height in mm): Slope 40: USNM 193984, 2.60,1.39; height 0.53% of length.
First Antenna: 1st joint without spines. 2nd joint with medial spines and 2 bristles (dorsal long with long spines; lateral short with triaenid type spines on distal 1/3). 3rd joint with distal margin defined better on medial side, with small bare ventral bristle and 6 dorsal bristles (2 widely separated single, then 4 in 2 distal pairs) with long spines. 4th joint longer than that of female, with straight distal margin, 2 small bare subterminal ventral bristles, and 1 long terminal dorsal bristle with short spines. 5th joint short (dorsal margin longer on medial side); sensory bristle stout with abundant slender filaments and few stouter filaments at tip. 6th joint with long medial bristle (with short spines) near dorsal margin. 7th joint: a-bristle on small pedestal, claw-like, spinous; b-bristle about 3 times length of a-bristle, with 5 marginal filaments, some with abundant spines; c –bristle extremely long (tip missing on both limbs of USNM 193984, with 41 or 42 short bare filaments on remaining parts). 8th joint (USNM 193984): Right limb: d-bristle ventral to e-bristle, about half its length and slenderer, bare with blunt tip; e-bristle twice length of a-bristle, bare with blunt tip. Left limb: d-bristle missing; e-bristle twice length of a-bristle, bare with blunt tip. 8th joint (continued): f-bristle similar to c -bristle (tip missing on left limb of USNM 193984, with 32 short bare filaments on remaining part); g-bristle about twice length of b-bristle (with tip missing on both limbs of USNM 193984, with 7 or 8 marginal filaments on remaining part). (The unusual ventral location of the d-bristle relative to the e-bristle of the 8th joint of the right limb of USNM 193984 is interpreted to be an aberrancy, as is the absence of a d-bristle on the left limb.)
Second Antenna: Protopodite with indistinct spines near dorsal margin and small distomedial bristle. Endopodite 3-jointed: 1st joint elongate bare; 2nd joint elongate with 3 short bristles; 3rd joint elongate, reflexed on 2nd joint, with slender proximal filament, and ridges along pointed tip. Exopodite: 2nd joint about 3 times length of 3rd joint; bristles of joints 2-8 long with natatory hairs, no spines; 9th joint with small lateral spine and 3 or 4 bristles with natatory hairs; joints 2-8 with few distal hairs and minute spines.
Mandible: Coxale endite: With small bristle at base of ventral branch; ventral branch with spines forming 7 rows, and tip with 2 long and 1 short spine (only 2 long shown); ventral margin of dorsal branch with 6 low nodes proximal to small main spine; edge between main spine and tip of branch with 2nd smaller spine similar to main spine, then row of small spines; tip of branch with small spines but no bristle; dorsal margin of dorsal branch with spinous bristle reaching well past tip of branch and serrations proximal to bristle. Basale endite with 4 spinous end bristles, small glandular peg, 2 dwarf bristles, and 2 triaenid bristles each with about 17 pairs of weak spines excluding terminal pair. Basale: Longer relative to width than basale of adult female and without proximal lateral and dorsal hairs, otherwise similar to that of female. Exopodite hirsute, about 1/3 length of dorsal margin of 1st endopodial joint, with 2 short subterminal bristles. 1st endopodial joint with 3 ventral bristles (2 with long spines except for short spines near tip, 1 with few long proximal spines and then short spines). 2nd endopodial joint: Ventral margin and medial surface similar to that of adult female; dorsal margin with 3 short slender spinous proximal bristles, stout spinous a-, b-, c-, and d-bristles (c-bristle shorter than d-bristle and with slightly stouter base), long slender spinous e-, f-, and g-bristles, and 10 cleaning bristles (oblique row of 4 between b- and c-bristles, and oblique row of 6 at base of c-bristle). 3rd endopodial joint similar to that of adult female.
Maxilla: Ventral margin of basale near midlength with 10 or 11 bristles and lateral side with proximal bristle; limb otherwise similar to that of adult female.
Fifth Limb: Comb similar to that of adult female.
Sixth Limb: Small bristle near proximal anterior comer. Anterior margin of both limbs of USNM 193984 with 1 bristle at both upper and lower sutures. Anteroventral comer with 3 small spinous bristles. Posteroventral margin with about 29 bristles.
Seventh Limb and Furca: Similar to those of adult female.
Bellonci Organ: Broader proximal to midlength than organ of adult female.
Eyes: Medial eye similar to that of adult female. Lateral eye larger than that of adult female, with 14 ommatidia, unpigmented.
Lips, Anterior of Body, and Y-Sclerite: Similar to those of adult female.
Genitalia: Triangular lobe (with 3 small proximal bristles) on each side of body anterior to furca.
Posterior of Body: Part ventral to girdle with crescentic ridges not observed on female; short spinous thumb-like dorsal process present.
COMPARISONS.—The basale of the mandible of A. efficax bears only 1 dorsal bristle at midlength compared to 3-5 bristles on previously described species of the genus. The basale of the maxilla of A. efficax bears fewer dorsal bristles and more ventral bristles than on the maxillae of previously described species of the genus.”
(Kornicker & Poore, 1996, p.143-150)
