“Vargula trifax, new species
FIGURES 16-20, 110o, p
ETYMOLOGY.—From the Latin trifax (a kind of spear).
HOLOTYPE.—Ovigerous female in alcohol in collection of the Museum of Victoria.
TYPE LOCALITY.—Slope 40, 38°17.70’S, 149°11.30’E, S of Point Hicks, Victoria; depth 400 m.
PARATYPES.—Slope 1: USNM 193905, ovigerous female on slide and in alcohol; 2 ovigerous females and 1 adult female (with female choniostomatid copepod and 2 choniostomatid ovisacs in marsupium) in alcohol; 3 adult females without eggs and 9 specimens (mostly juveniles) in alcohol. Slope 22: adult male in alcohol. Slope 40,40 specimens (mostly juveniles but including 3 ovigerous females) in alcohol. Slope 56, USNM 193948, 1 adult male on slide and in alcohol; 4 specimens in alcohol.
DISTRIBUTION.—Slope 1,204 m. Slope 22,363 m. Slope 40, 400 m. Slope 56,429 m. Known depth range 204-429 m.
DESCRIPTION OF ADULT FEMALE.—Carapace with small rostrum with lateral bulge and tubular caudal process. Height about 70% of length.
Infold: Rostral infold with 9-12 divided bristles forming row parallel to anterior edge of rostrum, about 6 divided bristles on or ventral to list, 8 smaller divided bristles posterior to row of longer bristles, and 2 long divided bristles posterior to smaller bristles; inner end of incisur with a pair of divided bristles. Anteroventral infold with 1-3 small bristles near incisur, 1 small bristle near inner margin of infold, and on right valve about 38 divided spinous bristles forming row extending along anterior 73 of valve (posterior 23 of these along subdued indistinct wavy list), and on left valve about 82 bristles in row extending full length of ventral margin (bristles more widely separated in posterior half of row; along anterior lh of valve most bristles along subdued indistinct wavy list); 2 bristles present dorsal to row of bristles in vicinity of bristles number 8 to 12 counting from anterior end of row. Broad sclerotized ridge along inner margin of posteroventral and posterior infold with 34 stout spines, some bifurcate; ridge narrows ventrally and continues along ventral margin of valve as bare narrow ridge along inner edge of infold. Ventral end of spinous part of ridge without closure as on V. trifax and is similar to ridge of V. tubulata (Poulsen, 1962, fig. 98c); dorsal end of ridge broad, triangular, with few small spines, and left valve with lip absent on right valve. Infold of caudal process posterior to list with straight line and numerous minute pores; 6-8 minute bristles just within posterior edge of caudal process. On left valve only list along middle 2/3 of ventral margin strongly crenulate; and in this area bristles not on list but about midway between list and valve edge.
Carapace Size (length, height in mm): Slope 1: USNM 193905, 5.2, 3.7; 5 specimens: 5.3, 3.7; 5.2, 3.5; 5.1, 3.5; 5.0, 3.6; length only, 5.2. Slope 40: 5.0, 3.2 (holotype). Height 67%-72% of length.
First Antenna: 1st joint bare. 2nd joint with ventral, dorsal, medial, and lateral spines. 3rd joint with 2 bristles (ventral subterminal or terminal, dorsal 1/4 to 1/3 joint length from proximal end) with short spines, neither bristle reaching distal edge of 4th joint 4th joint with 2 terminal bristles (dorsal bristle reaching middle of 6th joint, ventral about twice as long) with short spines. Sensory bristle of 5th joint with 9 stout proximal filaments, 3 slender distal filaments, and bifurcate tip. Medial bristle of 6th joint with short spines. 7th joint: a-bristle longer man bristle of 6th joint, with short spines; b-bristle with 3 or 4 filaments; c-bristle with 10 marginal filaments (most with spines) and bifurcate tip. 8th joint with minute papilla proximal to base of d-bristle; d- and e-bristles about same length as b-bristle, bare with blunt tips; f-bristle about same length as c-bristle, with 9 marginal filaments (most with spines) and bifurcate tip; g-bristle slightly longer than c-bristle, with 10 marginal filaments (most with spines) and bifurcate tip.
Second Antenna: Medial bristle of protopodite short with few indistinct spines. Endopodite 3-jointed: 1st joint with 4 bare proximal bristles (1 long, 3 short) and 1 long spinous distal bristle; 2nd joint with terminal bristle shorter than length of joint; 3rd joint with long terminal filament Exopodite: bristle of 2nd joint reaching past 9th joint, with 13 stout ventral spines; bristles of joints 3-8 and 4 bristles (3 long, 1 short) of 9th joint with natatory hairs, no spines; joints 2-8 with basal spines stouter on distal joints; spine of 8th joint reaching past end of 9th joint; lateral spine of 9th joint about 1/3 longer than joint
Mandible: Coxale endite with abundant slender spines and 2 slightly stouter terminal spines with small marginal spines; fairly long bare ringed bristle present near base of endite (about same length as longest of spines). Basale: ventral margin with 2 ringed spinous a-bristles, 1 small ringed bare b-bristlc close to a-bristles but with lateral base, 2 spinous c-bristles, and 2 spinous d-bristles (bases widely spaced; longer bristle with long proximal and short distal spines); dorsal margin with usual 3 bristles with short spines; medial surface with few distal rows of spines near dorsal margin. Exopodite slightly longer than length of dorsal margin of 1st endopodial joint, hirsute, with 2 subterminal bristles (distal 1/3 length of other) with short spines. 1st endopodial joint with 4 ventral bristles (1 minute bare, 1 short and 1 long with short spines, longest with short spines except for ring of long spines at distal 1/4). 2nd endopodial joint: ventral margin with 4 distal pointed bristles (2 single, 2 paired); medial of distal pair slightly longer and almost twice width of lateral; dorsal margin with 6 long bristles, 1 medium distal bristle, and 11 short bristles (most medial), none coarsely pectinate; ventral margin and medial surface spinous. 3rd endopodial joint with 3 stout claws (lateral with 5 proximal teeth (distal teeth stouter), others bare; dorsal claw about half length of longest claw), a stout dorsal claw-like bristle (with pointed tip) about 2/3 length of longest claw, and 3 ventral bristles (lateral bristle fairly stout proximaliy but not bulbous and no spines observed). Endopodite of left limb aberrant with few dorsal bristles on 2nd joint. Right limb with about half number of short bristles present on male mandible and may also be aberrant
Maxilla: Dorsal bristle of coxale plumose in proximal half and with minute spines on distal half. Endite I with 10 spinous bristles; endite II with 7 spinous bristles; endite III with 5 terminal bristles (4 stout spinous, 1 short, slender, bare). Basale with 1 short, slender, bare, lateral bristle near base of exopodite, 1 slender ventral bristle (with wreath of long spines) reaching 2nd endopodial joint, and 1 small medial bristle near long ventral bristle. Exopodite well developed, hirsute, with 3 equilength bristles (proximal and middle bristle with long hairs, other with few indistinct small spines). 1st endopodial joint with dorsal spines, few medial hairs near cutting tooth, 2 alpha-bristles (outer with abundant short hairs, inner with few indistinct minute hairs), and 3 pectinate beta-bristles; cutting tooth smoothly rounded. 2nd endopodial joint with 4 a-bristles (anterior bare, next with slender teeth, 3rd stout with strong teeth and narrow blunt tip, 4th with slender teeth), 3 pectinate ringed b-bristles, 3 pectinate ringed c-bristles (2 shorter than b-bristles), and 3 pectinate d-bristles (anterior 2 unringed, other ringed).
Fifth Limb: Epipodite with 71 bristles. Endite I with 6 spinous bristles; endite II with 4 spinous and pectinate bristles; endite III with 6 spinous and pectinate bristles. Protopodite with abundant anterior hairs and very large tooth. 1st endopodial joint: anterior side hirsute, with 3 bristles (all with long spines) in row, and 1 bristle (with long spines) closer to protopodial tooth; main tooth with smooth proximal peg, 6 pectinate teeth, and 1 bristle (with long proximal spines) proximal to peg. 2nd endopodial joint with 4 unringed pectinate a-bristles, 4 ringed pectinate b'-bristles, 4 ringed pectinate b"-bristles, 1 stout posterior c -bristle, and 1 anterior d-bristle with long hairs. 3rd endopodial joint: inner lobe with proximal plumose bristle and 2 terminal pectinate bristles (marginal teeth minute, not long like those of b"-bristles); outer lobe with 2 terminal bristles with long hairs or spines in proximal half and small distal spines. 4th and 5th joints hirsute, fused but location of boundary between them indicated by indentation in margin; 4th joint with 5 spinous bristles; 5th joint with 2 spinous bristles (neither with long spines) and small hirsute bulge near their bases.
Sixth Limb: With 8 epipodial bristles. Endite I with 2 or 3 medial bristles and 1 terminal bristle; endite II with 2 or 3 medial bristles and 3 terminal bristles; endite III with 1 medial bristle and 3 terminal bristles; endite IV with 1 medial bristle and 4 terminal bristles. End joint with 39 or 40 bristles (19 or 20 long bristles along edge (posterior 2 with only long hairs. 3 or 4 with only short spinet, others with long proximal hairs or spines and short distal spines); 9-11 short bristles medial to edge with short spines; and 8-11 short bristles lateral to edge with short spines). Medial side of limb hirsute; middle and posterior parts of distal edge of end joint with short rows of long spines.
Seventh Limb: USNM 193903: one limb with 48 bristles: terminal segment with 13 bristles on ventral edge of comb and 4 (3 on 1 side, 1 on other) at proximal end of comb; proximal segments with 11 bristles on comb side and 20 on jaw side. Other limb with 47 bristles: terminal segment with 13 bristles on ventral edge of comb and 4 (2 on each side) at proximal end of comb; proximal segments with 14 bristles on comb side and 16 on jaw side. Each bristle with up to 7 bells. Terminal comb with 8 flat-tipped teeth on each side of 11 or 12 longer alate teeth with rounded tips. Sclerotized ridge inside arc of comb with 2 stout distal teeth. Stout smooth claw-like jaw opposite comb.
Furca: Each lamella with 8 or 9 claws; claws 2, 4, and 5 nonarticulated; claw 3 slenderer than claw 4 but about same length; 1-3 small indistinct spinous processes between each pair of claws except between claws 1 and 2 and 2 and 3; 2 similar processes on lamella following last claw. Each claw with slender teeth along posterior edge; medial row of teeth of claw 1 close to posterior edge in proximal 1/4 then it bends anteriorly and continues distally closer to anterior edge; most claws with spines along anterior edge; anterior edge of lamellae with few minute spines; right lamella anterior to left by width of base of claw 1.
Bellonci Organ: Cylindrical with triangular tip.
Eyes: Lateral eye well developed with 13 large ommatidia and dark brown pigment, visible through shell. Medial eye short unpigmented.
Upper Lip: Anterior unpaired part a narrow ridge with very small glandular openings. Paired tusks hirsute (rows of anterior, posterior, and stouter lateral hairs), each with proximal triangular tooth and large terminal glandular process. Proximally on each side of lip a field of minute nodes.
Genitalia: Ring with attached spermatophore on each side of body anterior to furca.
Anterior of Body: A broad low anterior process ventral to 1st antenna. Brown pigmented area dorsal to medial eye (not part of eye).
Posterior of Body: Evenly rounded, bare.
Y-Sclerite: Typical for genus.
Number of Eggs: USNM 193905 with 34 eggs, each with black lateral eyes; length of 2 eggs 0.97 mm, 0.94 mm. Holotype: length of 2 eggs, each with lateral eyes: 0.66 mm, 0.68 mm.
Parasites: Marsupium of adult female from Slope 1 with female choniostomatid copepod and 2 choniostomatid ovisacs.
DESCRIPTION OF ADULT MALE.— Carapace similar in shape to that of adult female but smaller.
Carapace Size (length, height in mm): Slope 56: USNM 193948, 4.1, 2.8, height 68% of length. Slope 22: 4.5, 3.0, height 67% of length.
First Antenna: Joints 1-5 similar to those of adult female (right limb of USNM 193948 aberrant in having unusually long 3rd joint). 7th joint: a-bristle longer than bristle of 6th joint, with marginal spines; b-bristlc with stout proximal filament (with large diaphanous sucker with concentric rings and marginal fringe, small distal node, and pointed tip), followed by slender filament with about 14 minute suckers, then group of 3 filaments (2 short bare, 1 long with about 14 minute suckers); c -bristle longer than b-bristle, with stout proximal filament with large sucker similar to that of b-bristle, followed by 2 long filaments each with 14 or 15 minute suckers preceded by minute tooth, then 6 bare filaments and bifurcate tip (proximal bare filament close to 2nd filament with suckers). 8th joint: d- and e-bristles about half length of c-bristle, bare with blunt tips; f-bristle about same length as c -bristle, with 9 filaments (most with spines) and bifurcate tip; g-bristle about same length as c -bristle, with 10 filaments (most with spines) and bifurcate tip.
Second Antenna: Similar to that of adult female.
Mandible: 2nd endopodial joint: dorsal margin of 2nd endopodial joint with 6 long spinous bristles, 4 medium distal bristles, and 23 short bristles (most medial; 3 or 4 coarsely pectinate); medial bristle of terminal pair on ventral margin appearing more strongly sclerotized than that of adult female. Limb otherwise similar to that of adult female.
Maxilla: Endite I with 11 spinous bristles. Small medial bristle of basale near midwidth. Anterior 2 of 4 a-bristles of 2nd endopodial joint bare. Limb otherwise similar to that of adult female.
Fifth limb: Epipodial and endite bristles not counted. Protopodial tooth and exopodite similar to those of adult female.
Sixth limb: With 7 epipodial bristles. Endite I with 3 bristles (2 short medial, 1 long terminal); endite II with 3 short medial and 2 long terminal bristles; endite HI with 1 medial and 3 terminal bristles (middle bristle short); endite IV with 1 medial and 4 terminal bristles. End joint with 27-30 bristles (posterior 2 with only long hairs, others with either long proximal and short distal spines or only short spines). Hairs and spines of end joint similar to those of adult female.
Seventh limb: USNM 192948: one limb with 41 bristles: terminal segment not expanded in size, with 11 bristles on ventral edge of comb and 3 at proximal end of comb (2 on 1 side, 1 on other); proximal segments with 11 bristles on comb side and 16 on jaw side. Other limb also with 41 bristles: terminal segment with 13 bristles on ventral edge of comb and 3 at proximal end of comb (2 on 1 side, 1 on other); proximal segments with 10 bristles on comb side and 15 on jaw side. Each bristle with up to 6 bells. Terminal comb with 5 or 6 flat-tipped teeth on each side of about 13 longer alate teeth with rounded tips. Sclerotized ridge inside arc of comb and stout jaw opposite comb similar to those of adult female.
Furca: Similar to that of adult female except 3rd claw only very slightly narrower than claw 4 and spinous processes between claws not observed.
Bellonci Organ: Similar to mat of adult female.
Eyes: Lateral eye and medial eye similar to those of adult female. Lateral eye same length as that of female but smaller relative to size of carapace, which is smaller in male.
Upper Lip: Similar to that of adult female. (Tip of both tusks of USNM 193948 with glob that could have been extruded, but may be debris.)
Genitalia: Small copulatory organ on each side of body anterior to furca (not studied in detail).
Anterior of Body, Y-Sclerite: Similar to those of adult female.
Posterior of Body: With 7 segments on each side continuous across posterior of body where each segments bends ventrally; rounded posterior end of each segment viewed posteriorly forms visible edge.
COMPARISONS.—The female V. trifax shares many characters with, and differs from the female V. tubulata Poulsen, 1962:198, mainly in the furca (5th claw articulated in tubulata, nonarticulated in trifax). The length of the carapace of the female tubulata is 4.17 mm, shorter than trifax, which is 5.0-5.3 mm in length. (Dr. Anne C. Cohen has reexamined the holotype of V. tubulata and verified that the 5th claw of the furca is articulated (in lit 1990).)”
(Kornicker, 1994, p. 33-39)
