Harbansus hapax Kornicker 1995

“Harbansus hapax, new species

Figures 21-23

Harbansus species A.—Kornicker, 1994, fig. 109f.

ETYMOLOGY.—From the Greek hapax (once only).

HOLOTYPE.—Undissected ovigerous female in alcohol in collection of the Museum of Victoria.

TYPE LOCALITY.—Slope 53, 34°52.72'S, 151°15.04'E, New South Wales, 54 km ESE of Nowra; depth 996 m.

PARATYPES.—USNM 193998, ovigerous female on slide and in alcohol.

DISTRIBUTION.—Slope 53, 996 m. Slope 56,429 m.

DESCRIPTION OF ADULT FEMALE.— Carapace elongate with prominant rostrum and broad caudal process.

Ornamentation: Rostrum with lateral rib curving around incisur and forming low rib at anteroventral comer of valve; rostrum of left valve broader than that of right, and with narrow irregular low rib near dorsal margin; anteroventral tip of rostrum extending laterally past oblique valve edge. Surface with large irregular fossae (fossae on USNM 193998 filled with debris appearing brown in transmitted light). Long single bristles sparsely distributed on valve surface, and more numerous (about 13 bristles) along ventral margin.

Infold: Rostral infold with row of 4 long spinous bristles parallel to anterior margin, and a pair of bristles at inner end of incisur (these appear to be external to lamellar prolongation of selvage); anteroventral infold with 1 small bristle near inner end of incisur and 5 or 6 narrow ridges (no bristles near ridges). Infold of caudal process with 6 frond-like bristles along ridge forming "pocket"; additional small bristles near inner margin of infold anterior to caudal process.

Selvage: Lamellar prolongation with marginal fringe present along anterodorsal, anterior, and ventral margins, and along posterior margin dorsal to caudal process; prolongation absent along posterior edge of caudal process; prolongation very broad in vicinity of incisur and divided at inner end of incisur.

Central Adductor Muscle Attachments: Comprising about 27 oval attachments.

Carapace Size (length, height in mm): Slope 53, holotype, 1.42, 0.87. Slope 56, USNM 193998, 1.45, 0.89.

First Antenna: 1st joint with lateral and medial rows of spines. 2nd joint with dorsal, ventral, medial, and lateral slender spines, and 1 spinous dorsal bristle. 3rd joint with ventral spines, short row of lateral spines in distal ventral corner, and 3 spinous bristles (1 ventral, 2 dorsal). 4th joint with ventral and dorsal spines and 3 spinous bristles (2 ventral, 1 dorsal). Ventral bristle of 5th joint with 2 proximal and 2 or 3 subterminal filaments and 2 minute spines at tip. 6th joint fused to 5th, with short slender medial bristle. 7th joint: a-bristle 1/4 to 1/2 longer than bristle of 6th joint, with short spines; b-bristle about twice length of a-bristle, with 1 short distal filament and 2 minute spines at tip; c -bristle about same length as bristle of 5th joint, with 1 or 2 proximal and 3 distal filaments and 2 minute spines at tip. 8th joint: d- and e-bristles as long as c-bristle, bare with blunt tips; f-bristle about same length as c-bristle, with 2 proximal and 2 or 3 distal filaments and 2 minute spines at tip; g-bristle slightly longer than f-bristle, with 2 proximal and 2 distal filaments and 2 minute spines at tip.

Second Antenna: Protopodite bare. Endopodite 2-jointed: 1st joint with 3 short proximal bristles (bare or with indistinct spines); 2nd joint elongate with long spinous ventral bristle in proximal 1/3 and broadly rounded bare tip. Exopodite: 1st joint with minute recurved terminal medial bristle with tubular tip; bristles of joints 2-8 about same length as combined lengths of joints 1 and 2, with slender ventral and dorsal spines, none or few (1-4) long proximal dorsal hairs, and without distal hairs (most exopodial bristles of left limb of USNM 193998 bare, probably aberrancy); 9th joint with 3 bristles (ventral bristle slightly shorter than bristle of 8th joint, with slender ventral and dorsal spines; middle and dorsal bristle short, with short ventral and dorsal spines; joints 2-8 with short spines along distal margins; basal spines absent; exopodial bristles with closely spaced rings (not with long joints like those of H. tenax). (Note: absence of distal hairs on exopodial bristles indicates female to be nonswimmer.)

Mandible: Coxale endite bifurcate, spinous, without small bristle at base. Basale: dorsal margin with 3 bristles (1 at distal 2/3, 2 terminal); ventral margin and medial surface near ventral margin with total of 5 bristles (3 proximal and 1 near midlength short, 1 distal longer); lateral surface with 2 bristles (with long proximal and short distal spines) extending past ventral margin; medial surface spinous. Exopodite spinous, reaching past midlength of dorsal margin of 1st endopodial joint, with 2 bristles (proximal longer and with long spines). 1 st endopodial joint with medial spines and 3 ventral bristles (2 long, 1 short). 2nd endopodial joint: dorsal margin with spines, and 7 bristles near midlength; ventral margin with spines, and 4 short bristles in 2 groups (2 spinous bristles in each group; outer slightly medial bristle in distal group broader, unringed, and about twice length of inner bristle); medial surface with rows of spines. 3rd endopodial joint with small dorsal claw, 2 long claws with proximal ventral spines, and 3 slender ringed bristles.

Maxilla: Precoxale and coxale with fringe of dorsal hairs. Coxale with dorsal bristle, and 1 lateral bristle near midheight. Endite I broader than endites II and III, with 6 spinous distal bristles; endites II and III with 5 or 6 spinous or pectinate distal bristles. Basale with 3 spinous bristles along distal margin (1 dorsal, 1 medial ventral, 1 lateral ventral). Exopodite small with 3 bristles (2 long, 1 short). 1st endopodial joint with 1 alpha-bristle with long and short spines and 2 beta-bristles with short spines. 2nd endopodial joint with 3 stout unringed claws (lb, 2d) and 6 ringed bristles (2a, lb, 2c, 1d).

Fifth Limb: With 3 endites (bristles not counted). 1st exopodial joint: main tooth complex with 1 smooth spine-like proximal tooth, 1 pectinate middle tooth, and 1 pectinate large bifurcate distal tooth; ringed bristle proximal to spine-like tooth; anterior side of joint with pair of long bristles along distal edge near midwidth. 2nd exopodial joint with large flat tooth with uneven inner margin; posterior side with row of 3 bristles (long bristle in middle, 1 short bristle on each side) and long bristle proximal to row. 3rd exopodial joint with 3 bristles on inner lobe and 2 on smaller outer lobe. 4th and 5th exopodial joints fused, with total of 5 bristles with long proximal spines.

Sixth Limb: With 1 short epipodial bristle with long hairs. Endites I and II each with 3 spinous bristles; endite III with 5 or 6 spinous bristles; endite IV about same width or slightly broader than endite III, with 5 spinous bristles. End joint not prolonged posteriorly, with 4 anterior spinous bristles followed by space and 2 stout plumose bristles; anteroventral comer with small spinous process. Limb hirsute.

Seventh Limb: Proximal group with 4 bristles (on segments 7-10 counting from segment proximal to terminal segment), 2 on each side, each with distal spines and 2 (usual) or 4 bells. Terminal group with 4 bristles, 2 on each side, each with distal spines and 3 or 4 bells. Some tufts protruding from terminal bells with spines, others similar in shape to bell but smaller. Terminal segment with comb with 5 alate teeth opposite comb with 3 smaller alate teeth.

Furca: Each lamella with 8 or 9 claws; claws 1,2, and 4 stout, remaining claws short slender, all claws with teeth along posterior edge (tooth at midlength of claw 1 not stouter than some of the more proximal teeth; length of tooth less than width of claw at midlength); claw 1 with row of medial teeth (1 distal medial tooth large, pointing downward); spines present on lamella following claws, and on anterior margin; right lamella with medial spines near anterior edge, and anterior to left lamella by width of base of claw 1.

Bellonci Organ: Elongate with 5 or 6 proximal sutures and rounded tip.

Eyes: Lateral eyes absent Medial eye unpigmented.

Upper Lip: Single hirsute lobe tapering anteriorly and with glandular processes at tip.

Genitalia: Rimmed oval at each side of body anterior to furca.

Anterior of Body: Single large rounded anterior process present ventral to bases of 1st antennae.

Posterior of Body: Posterodorsal corner with long spines.

Y-Sclerite: With ventral branch.

Number of Eggs: Holotype with 2 eggs in marsupium, length of 1 egg measured through shell 0.29 mm. USNM 193998 with 2 eggs in marsupium, length of 1 egg 0.32 mm.

COMPARISONS.—In the key to species of Harbansus in Komicker (1992:97) H. hapax keys out to H. schornikovi (Kornicker and Caraion, 1977:27). It differs from that species in having 8 or 9 claws instead of 6 on each lamella of the furca. Four previously described species from the vicinity of Australia, H. felix, H. slatteryi, H. tenax, and H. vatrax, also have only 6 furcal claws. The carapace of H. hapax is without either the lateral alar process ofH. felix or the lateral ribs of H. slatteryi and H. vatrax. The anterior tip of the rostrum of H. tenax does not overlap the oblique valve edge as on H. hapax.”

(Kornicker, 1995, pp. 35-39)

Harbansus hapax

Harbansus species A.—Kornicker, 1994, fig. 109f.

ETYMOLOGY.—From the Greek hapax (once only).

HOLOTYPE.—Undissected ovigerous female in alcohol in collection of the Museum of Victoria.

TYPE LOCALITY.—Slope 53, 34°52.72–S, 151°15.04–E, New South Wales, 54 km ESE of Nowra; depth 996 m.

PARATYPES.—USNM 193998, ovigerous female on slide and in alcohol.

DISTRIBUTION.—Slope 53, 996 m. Slope 56, 429 m.

DESCRIPTION OF ADULT FEMALE (Figures 21–23).—Carapace elongate with prominant rostrum and broad caudal process (Figure 21a,c).

Ornamentation: Rostrum with lateral rib curving around incisur and forming low rib at anteroventral corner of valve (Figure 21a,b); rostrum of left valve (Figure 21d) broader than that of right (Figure 21b), and with narrow irregular low rib near dorsal margin (Figure 21a); anteroventral tip of rostrum extending laterally past oblique valve edge (Figure 21d,f). Surface with large irregular fossae (Figure 21a,b) (fossae on USNM 193998 filled with debris appearing brown in transmitted light). Long single bristles sparsely distributed on valve surface, and more numerous (about 13 bristles) along ventral margin (not all shown in Figure 21a).

Infold: Rostral infold with row of 4 long spinous bristles parallel to anterior margin, and a pair of bristles at inner end of incisur (these appear to be external to lamellar prolongation of selvage)(Figure 21d,f); anteroventral infold with 1 small bristle near inner end of incisur and 5 or 6 narrow ridges (no bristles near ridges). Infold of caudal process with 6 frond-like bristles along ridge forming “pocket” (Figure 21e); additional small bristles near inner margin of infold anterior to caudal process.

Selvage: Lamellar prolongation with marginal fringe present along anterodorsal, anterior, and ventral margins, and along posterior margin dorsal to caudal process; prolongation absent along posterior edge of caudal process; prolongation very broad in vicinity of incisur and divided at inner end of incisur (Figure 21f).

Central Adductor Muscle Attachments (Figure 21g): Comprising about 27 oval attachments.

Carapace Size (length, height in mm): Slope 53, holotype, 1.42, 0.87. Slope 56, USNM 193998, 1.45, 0.89.

First Antenna (Figure 21h): 1st joint with lateral and medial rows of spines. 2nd joint with dorsal, ventral, medial, and lateral slender spines, and 1 spinous dorsal bristle. 3rd joint with ventral spines, short row of lateral spines in distal ventral corner, and 3 spinous bristles (1 ventral, 2 dorsal). 4th joint with ventral and dorsal spines and 3 spinous bristles (2 ventral, 1 dorsal). Ventral bristle of 5th joint with 2 proximal and 2 or 3 subterminal filaments and 2 minute spines at tip. 6th joint fused to 5th, with short slender medial bristle. 7th joint: a-bristle to longer than bristle of 6th joint, with short spines; b-bristle about twice length of a-bristle, with 1 short distal filament and 2 minute spines at tip; c-bristle about same length as bristle of 5th joint, with 1 or 2 proximal and 3 distal filaments and 2 minute spines at tip. 8th joint: d- and e-bristles as long as c-bristle, bare with blunt tips; f-bristle about same length as c-bristle, with 2 proximal and 2 or 3 distal filaments and 2 minute spines at tip; g-bristle slightly longer than f-bristle, with 2 proximal and 2 distal filaments and 2 minute spines at tip.

Second Antenna: Protopodite bare (Figures 21i, 23g). Endopodite 2-jointed (Figure 21i): 1st joint with 3 short proximal bristles (bare or with indistinct spines); 2nd joint elongate with long spinous ventral bristle in proximal and broadly rounded bare tip. Exopodite: 1st joint with minute recurved terminal medial bristle with tubular tip; bristles of joints 2–8 about same length as combined lengths of joints 1 and 2, with slender ventral and dorsal spines, none or few (1–4) long proximal dorsal hairs, and without distal hairs (most exopodial bristles of left limb of USNM 193998 bare, probably aberrancy); 9th joint with 3 bristles (ventral bristle slightly shorter than bristle of 8th joint, with slender ventral and dorsal spines; middle and dorsal bristle short, with short ventral and dorsal spines; joints 2–8 with short spines along distal margins; basal spines absent; exopodial bristles with closely spaced rings (Figure 21j) (not with long joints like those of H. tenax). (Note: absence of distal hairs on exopodial bristles indicates female to be nonswimmer.)

Mandible (Figure 22a): Coxale endite bifurcate, spinous, without small bristle at base. Basale: dorsal margin with 3 bristles (1 at distal , 2 terminal); ventral margin and medial surface near ventral margin with total of 5 bristles (3 proximal and 1 near midlength short, 1 distal longer); lateral surface with 2 bristles (with long proximal and short distal spines) extending past ventral margin; medial surface spinous. Exopodite spinous, reaching past midlength of dorsal margin of 1st endopodial joint, with 2 bristles (proximal longer and with long spines). 1st endopodial joint with medial spines and 3 ventral bristles (2 long, 1 short). 2nd endopodial joint: dorsal margin with spines, and 7 bristles near midlength; ventral margin with spines, and 4 short bristles in 2 groups (2 spinous bristles in each group; outer slightly medial bristle in distal group broader, unringed, and about twice length of inner bristle); medial surface with rows of spines. 3rd endopodial joint with small dorsal claw, 2 long claws with proximal ventral spines, and 3 slender ringed bristles.

Maxilla (Figure 22b–d): Precoxale and coxale with fringe of dorsal hairs. Coxale with dorsal bristle, and 1 lateral bristle near midheight (Figure 22b). Endite I broader than endites II and III, with 6 spinous distal bristles; endites II and III with 5 or 6 spinous or pectinate distal bristles. Basale with 3 spinous bristles along distal margin (1 dorsal, 1 medial ventral, 1 lateral ventral). Exopodite small with 3 bristles (2 long, 1 short (Figure 22b)). 1st endopodial joint with 1 alpha-bristle with long and short spines and 2 beta-bristles with short spines. 2nd endopodial joint with 3 stout unringed claws (1b, 2d) and 6 ringed bristles (2a, 1b, 2c, 1d) (Figure 22c,d).

Fifth Limb: With 3 endites (bristles not counted). 1st exopodial joint: main tooth complex with 1 smooth spine-like proximal tooth, 1 pectinate middle tooth, and 1 pectinate large bifurcate distal tooth (Figure 23b,c); ringed bristle proximal to spine-like tooth; anterior side of joint with pair of long bristles along distal edge near midwidth (Figure 23b). 2nd exopodial joint with large flat tooth with uneven inner margin (Figure 23a,c); posterior side with row of 3 bristles (long bristle in middle, 1 short bristle on each side) and long bristle proximal to row (Figure 23a). 3rd exopodial joint with 3 bristles on inner lobe and 2 on smaller outer lobe. 4th and 5th exopodial joints fused, with total of 5 bristles with long proximal spines (Figure 23a).

Sixth Limb (Figure 22e): With 1 short epipodial bristle with long hairs. Endites I and II each with 3 spinous bristles; endite III with 5 or 6 spinous bristles; endite IV about same width or slightly broader than endite III, with 5 spinous bristles. End joint not prolonged posteriorly, with 4 anterior spinous bristles followed by space and 2 stout plumose bristles; anteroventral corner with small spinous process. Limb hirsute.

Seventh Limb (Figure 23d): Proximal group with 4 bristles (on segments 7–10 counting from segment proximal to terminal segment), 2 on each side, each with distal spines and 2 (usual) or 4 bells. Terminal group with 4 bristles, 2 on each side, each with distal spines and 3 or 4 bells. Some tufts protruding from terminal bells with spines, others similar in shape to bell but smaller. Terminal segment with comb with 5 alate teeth opposite comb with 3 smaller alate teeth.

Furca (Figure 23e,f): Each lamella with 8 or 9 claws; claws 1, 2, and 4 stout, remaining claws short slender, all claws with teeth along posterior edge (tooth at midlength of claw 1 not stouter than some of the more proximal teeth; length of tooth less than width of claw at midlength); claw 1 with row of medial teeth (1 distal medial tooth large, pointing downward); spines present on lamella following claws, and on anterior margin; right lamella with medial spines near anterior edge, and anterior to left lamella by width of base of claw 1. (Second claw in Figure 23e,f is on left lamella.)

Bellonci Organ (Figure 23h): Elongate with 5 or 6 proximal sutures and rounded tip.

Eyes: Lateral eyes absent. Medial eye unpigmented (part of eye missing in Figure 23h).

Upper Lip (Figure 23h): Single hirsute lobe tapering anteriorly and with glandular processes at tip.

Genitalia (Figure 23e): Rimmed oval at each side of body anterior to furca.

Anterior of Body (Figure 23g,h): Single large rounded anterior process present ventral to bases of 1st antennae.

Posterior of Body (Figure 22f): Posterodorsal corner with long spines.

Y-Sclerite (Figures 22f, 23e): With ventral branch.

Number of Eggs: Holotype with 2 eggs in marsupium, length of 1 egg measured through shell 0.29 mm. USNM 193998 with 2 eggs in marsupium, length of 1 egg 0.32 mm (outline of egg shown in Figure 21a).

COMPARISONS.—In the key to species of Harbansus in Kornicker (1992:97) H. hapax keys out to H. schornikovi (Kornicker and Caraion, 1977:27). It differs from that species in having 8 or 9 claws instead of 6 on each lamella of the furca. Four previously described species from the vicinity of Australia, H. felix, H. slatteryi, H. tenax, and H. vatrax, also have only 6 furcal claws. The carapace of H. hapax is without either the lateral alar process of H. felix or the lateral ribs of H. slatteryi and H. vatrax. The anterior tip of the rostrum of H. tenax does not overlap the oblique valve edge as on H. hapax.