“Metavargula apex Kornicker, new species
Figures 11, 12
Metavargula species D, Kornicker, 1994, fig. 110jj-ll.
ETYMOLOGY.—From the Latin apex (tip, top).
HOLOTYPE.—NMV J35987, undissected adult female.
TYPE LOCALITY.—Slope 56, 34°55.79'S, 151°08.06'E,New South Wales, 44 km E of Nowra; depth 429 m.
PARATYPES.—Slope 46: USNM 193854,1 ovigerous female on slide and in alcohol. Slope 56: USNM 193950, 1 adult male on slide and in alcohol; USNM 193951,1 adult female on slide and in alcohol; NMV J37159, 2 ovigerous females plus 3 juveniles in alcohol.
DISTRIBUTION.—Slope 46, 720 m. Slope 56,429 m.
DESCRIPTION OF ADULT FEMALE.— Carapace oval with small incisur and upsweeping caudal process. Outer surface of shell with weakly developed scallops in posterior part.
Infold: Narrow list with anterior end at about midheight of anteroventral margin continues along ventral margin to point about 2/3 valve length, then broadens to form flange along posteroventral infold and infold of caudal process (flange broadest along anterior edge of caudal process). Rostral infold with 12 bristles (mostly divided) in row along anterior and ventral margins, 1 long divided bristle at midwidth, 0 or 1 small bristle at midheight near inner margin of infold, 1 small bristle proximal to inner end of incisur, and 1 pair of bristles near inner end of incisur (in Figure l i e some bristles represented by sockets). Anteroventral and anterior half of ventral infold with 14 bristles (all except anterior 2 with base along narrow list; anterior 3 bristles of left valve shown in Figure lie). Ventral infold between valve midlength and anterior end of flange with about 7 bristles along list and 4 bristles along inner margin. Posterior edge of posteroventral infold and infold of caudal process with about 10 minute bristles (not shown). Posterior edge of flange anterior to caudal process with 16-18 minute pore openings, each on small process; anterior edge of flange with 3 small bristles and narrow bulge near dorsal end. Ventral infold just anterior to caudal process with 1 small bristle near outer edge.
Selvage: Similar to that of M. spadix.
Carapace Size (length, height in mm): Slope 46: USNM 193854, 2.97, 1.64, height 55% of length. Slope 56: USNM 193951, 2.84, 1.52, height 54% of length; NMV J37159 (both specimens), 2.91,1.57, height 54% of length; 2.94,1.58, height 54% of length (specimen 1); NMV J35987 (holotype), length 2.85, 1.61, height 56% of length. Length range 2.84-2.97; height range 1.52-1.61.
First Antenna: Joints 1-6 similar to those of M. spadix. 7th joint: a-bristle about 1/3 longer than bristle of 6th joint; b-bristle about 1/3 longer than a-bristle, with 4 marginal filaments, some with spines; c -bristle long with 8 marginal filaments (some with spines) and bifurcate tip. 8th joint: d-and e-bristles about 1/4 longer than b-bristle, bare with blunt tips; f-bristle about 2/3 length of c-bristle, with 7 marginal filaments (some with spines) and bifurcate tip; g-bristle same length as c -bristle, with 9 marginal filaments (some with spines) and bifurcate tip.
Second Antenna: Similar to that of M. spadix.
Mandible: Coxale similar to that of M. spadix. Basale of right limb but not of left limb of USNM 193854 and both limbs of USNM 193951 with small c -bristle proximal rather than distal to long bristle (basale otherwise similar to that of M. spadix). Exopodite just reaching past distal end of dorsal margin of 1st endopodial joint, slightly shorter than that of M. spadix. 1st, 2nd, and 3rd endopodial joints similar to those of M. spadix, except 7 dorsal spines on broad medial bristle of terminal pair on ventral margin of 2nd joint of USNM 193854.
Maxilla: Endite bristles not counted (obscured on USNM 193854) but appearing similar to those of M. spadix. Protopodite, basale, and exopodite similar to those of M. spadix. 1st endopodial joint: Cutting tooth with 2 (rarely 1) triangular cusps; alpha- and beta-bristles similar to those of M. spadix except no spines observed on inner beta-bristle. 2nd endopodial joint: 2 posterior a-bristles spinous, next bare or with few proximal spines, and anterior bristle bare; 3 b- and 3 d-bristles similar to those of M. spadix;
2 c -bristles ringed pectinate (3rd small bare anterior bristle present on M spadix absent).
Fifth Limb: Epipodite with 60 bristles. Protopodite with short anterior tooth. Endite I with 5 spinous bristles (proximal anterior bristle small); endite II with 5 spinous bristles (proximal anterior bristle small); endite III with 6 spinous bristles. 1st and 2nd exopodial joints similar to those of M. spadix except proximal triangular tooth of main tooth may have a minute spine at tip (visible only at high magnification (xIOO objective, xl5 ocular)). 3rd exopodial joint similar to that of M. spadix except inner bristle of outer lobe with short spines and outer bristle of inner lobe may be bare or have 2 minute spines. 4th and 5th exopodial joints similar to those of M. spadix except 4th joint with only 2 bristles, both with short spines.
Sixth Limb: With 3 bare epipodial bristles. Endite I with 2 short medial bristles and 1 long terminal bristle; endite II with 3 short medial bristles and 2 long terminal bristles; endite III with 3 terminal bristles (middle bristle shorter); endite IV with 3 terminal bristles (middle bristle shorter). End joint with 6 or 7 bristles with long proximal and short distal spines (anterior bristle shorter and may be without long spines) followed by space and 3 bristles (anterior of these with long proximal and short distal spines, others plumose).
Seventh Limb: USNM 193854: One limb with 16 bristles (terminal group with 6 bristles on comb side and 7 (2 fused in proximal 1/3) on peg side; proximal group with 1 bristle on comb side and 2 on peg side). Other limb with 15 bristles (terminal group with 6 bristles on comb side and 5 on peg side; proximal group with 2 bristles on comb side and 2 on peg side). Each bristle with up to 6 bells. Comb with 4-6 slender spinous ringed teeth with slightly bulbous tips; single slender elongate peg (with slightly bulbous tip) opposite comb. USNM 193951: One limb with 17 bristles (terminal group with 5 bristles on each side; proximal group with 2 bristles on comb side and 5 on peg side). Other limb also with 17 bristles (terminal group with 6 bristles on comb side and 5 on peg side; proximal group with 2 bristles on comb side and 4 on peg side). Each bristle with up to 6 bells. Comb with 6 teeth opposite single peg.
Furca: Similar to that of M. spadix.
Bellonci Organ: Cylindrical with minute pointed process at tip.
Eyes: Medial eye well developed, either with brown pigment in area indicated by stippling in Figure 11j [in cited text] (USNM 193854), or light amber colored (USNM 193951). Lateral eye of USNM 194854 small with reddish brown pigment obscuring internal structures (pigment appears in 3 poorly defined oval areas containing a total of 4 or 5 small amber cells). Lateral eye of USNM 193951 small and containing 2 or 3 oval brown areas.
Upper Up: Each tusk with small glandular processes projecting from posterior edge and 2 terminal glandular processes.
Genitalia: USNM 193954 with attached spermatophore.
Anterior and Posterior of Body: Similar to those of M. spadix.
Y-Sclerite: Typical for subfamily.
Eggs: Slope 46: USNM 193854 with 9 eggs (with shells developed) in marsupium; length of typical egg 0.53 mm. Slope 56: NMV J37159, 1 specimen with 7 eggs in marsupium (typical length 0.35 mm), and 1 specimen with 5 eggs in marsupium (typical length 0.33 mm).
DESCRIPTION OF ADULT MALE.—Carapace similar in shape to that of adult female but smaller.
Infold: Posterior edge of flange anterior to caudal process with about 14 small projecting processes. Bristles of infold not counted.
Carapace Size (length, height in mm): USNM 193950, 2.08, 1.08. height 52% of length.
First Antenna: 1st and 2nd joints bare. 3rd joint with terminal ventral bristle and dorsal bristle at 1/4 length of dorsal margin; 4th joint with 2 terminal bristles (1 ventral, 1 dorsal). Sensory bristle of 5th joint about 5 times length of a-bristle of 7th joint and stouter proximal to marginal filaments, with 8 proximal broad paddle-like filaments, 2 distal slender bare filaments, and bifurcate tip. Medial bristle of 6th joint close to dorsal margin, bare. 7th joint: a-bristle about 1 1/2 times length of bristle of 6th joint, bare; b-bristle about 3 times length of a-bristle, with 4 filaments (proximal filament stout with bulbous proximal part followed by large sucker and small protuberance; 2nd filament slender with small spine and 2 small suckers; 3rd filament slender with 2 or 3 small suckers; 4th filament short slender bare) and undivided tip; c-bristle about 4 times length of b-bristle, with 8 marginal filaments (proximal filament similar to that of proximal filament of b-bristle but with larger sucker, followed by 2 slender filaments each with 2 small suckers, then 5 slender filaments, each with single marginal spine) and bifurcate tip. 8th joint: d- and e-bristles slightly longer than b-bristle, bare with blunt tips; f-bristle about 3 1/2 times length of b-bristle, with 8 spinous filaments and bifurcate tip; g-bristle same length as c-bristle, with 8 slender spinous filaments and bifurcate tip.
Second Antenna: Protopodite with small swelling at midlength of dorsal margin (also present on protopodite of adult female) and with minute medial distal bristle. Limb similar to that of adult female.
Mandible: Short c-bristle of basale distal to long c-bristle. Dorsal margin of 2nd endopodial joint with only 6 short bristles in addition to 5 long bristles. Limb otherwise similar to that of adult female.
Maxilla: Cutting tooth of 1st endopodial joint bifurcate. Limb similar to that of adult female including having only 2 c-bristles.
Fifth Limb: Proximal tooth of main tooth with or without terminal spine. Outer bristle of inner lobe of 3rd exopodial joint with few spines. Limb otherwise similar to that of adult female.
Sixth Limb: With 2 or 3 epipodial bristles. Endite II with 2 short medial bristles and 1 long terminal bristle; endites I, III, and IV similar to those of adult female. End joint of left limb of USNM 193950 with 8 anterior bristles with long proximal and short distal spines followed by space and 3 bristles (anterior of these with long proximal and short distal spines, others plumose); right limb of USNM 193950 differs in having only 6 bristles in anterior group including 1 near anterior end with only short spines. 6th limb of male otherwise similar to that of adult female.
Seventh Limb: USNM 193950, each limb with 13 bristles (10 bristles (4 or 5 on comb side, 5 or 6 on peg side) in terminal group and 3 in proximal group (1 on comb side, 2 on peg side)); each bristle with up to 6 bells. Comb with 4 ringed teeth with slightly bulbous tips; single slender elongate peg (with slightly bulbous tip) opposite comb.
Furca: Similar to that of adult female.
Bellonci Organ: Cylindrical with blunt tip.
Eyes: Medial eye well developed, with light amber color. Lateral eye small with brown pigment in 3 amber colored areas.
Upper Lip: Similar to that of adult female.
Genitalia: Elongate copulatory organ on each side of body anterior to furca.
Anterior of Body: Similar to that of adult female.
Posterior of Body: Dorsal part of body anterior to dorsal end of girdle with about 27 narrow crenulations.
Y-Sclerite: Similar to that of adult female.
COMPARISONS.—The carapace of M. apex differs from that of M. spadix in having stouter processes along the posterior edge of the flange of the infold anterior to the caudal process; the edge is usually smooth on M. spadix. The 7th limb of the female M. apex bears 15-17 bristles compared to 24-29 on M. spadix. The length of the female M. calix is 5.12 mm, much larger than that of M apex, and the 6th limb bears 6 epipodial bristles compared to 3 on M. apex. The maxilla of M. apex has 2 c-bristles compared to 3 on both M. spadix and M. calix.”
(Kornicker & Poore, 1996, p.29-33)
