Spinacopia rex Kornicker 1995

“Spinacopia rex, new species

Figures 26-30

ETMOLOGY.—From the Latin rex (king).

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

TYPE LOCALITY.—Slope 27, 38°25.00'S, 149°0.00'E, Victoria, south of Point Hicks, depth 1500 m.

PARATYPES.—Slope 25: 4 specimens in alcohol. Slope 27: USNM 193868, adult female on slide and in alcohol; 4 specimens including adult females and juveniles in alcohol. Slope 32: USNM 193834, adult female in alcohol (body removed from shell); 12 specimens including adult females and juveniles in alcohol. Slope 67: 4 undissected specimens in alcohol. Slope 69: USNM 193945,1 adult male on slide and in alcohol; 12 specimens including adult females and juveniles in alcohol. Slope 81: 2 adult females and 2 juveniles. Slope 82: 2 adult females (1 ovigerous) and 4 juveniles.

DISTRIBUTION.—Slope 25,1850 m. Slope 27,1500 m. Slope 32, 1000 m. Slope 67, 1277 m. Slope 69, 1840 m. Slope 81, 1264 m. Slope 82, 1770 m. Known depth range 1000-1850 m.

DESCRIPTION OF ADULT FEMALE.— Carapace oval in lateral view with greatest height near midlength; anterior margin with obtuse angle dorsal to minute indentation marking incisur; posterior with short caudal process; adult female with large posterodorsal bulge well defined along ventral edge by steep slope; hairs along ventral margin of bulge about same length as hairs on remaining part of bulge. Surface without gel-like coating.

Ornamentation: Shallow fossae (without peripheral circle of small spines) distributed over valve surface. Long hairs with proximal enlargement (a-hairs) common along valve edge and present but less common on lateral surface; short-to-medium hairs tapering at a more-or-less constant angle from base to tip (b-hairs) abundant; hairs not arranged in bunches or rows. (For explanation of lettering system for hairs see Kornicker (1975:583).)

Infold: Anterior infold ventral to minute incisur with small bristle near inner margin. Infold of caudal process with a row of 4 or 5 long and 4 short spinous bristles. Small bristles along inner margin of infold anterior to caudal process.

Central Adductor Muscle Attachments: Not clearly seen but comprising about 13 oval attachments.

Carapace Size (length, height including caudal process, mm): Slope 27: holotype, 1.94, 1.71; USNM 193868, 1.86, 1.67; unnumbered specimen, 1.83, 1.51. Slope 32: USNM 193834, 1.77, 1.65; unnumbered specimen, 1.80, 1.62. Slope 81: 2 specimens, 1.93, 1.62; 1.93, 1.56. Slope 82: 1.82, 1.64.

First Antenna: 1st joint bare. 2nd joint with spines on ventral and dorsal margins and on lateral side near ventral and dorsal margins, and 1 dorsal bristle with long proximal and short distal spines. 3rd joint fused to 4th, with 2 long bristles with short spines (1 ventral, 1 dorsal). 4th joint with 3 spinous bristles (2 ventral, 1 dorsal). Sensory bristle of 5th joint with small proximal filament and 1 or 2 minute distal spines. 6th joint fused to 5th, with minute medial spine-like bristle (easily overlooked). 7th joint: a-bristle spinous, about 1/3 length of sensory bristle of 5th joint; b-bristle longer than a-bristle but not reaching midlength of sensory bristle, with minute spine near midlength; c -bristle same length as sensory bristle, with 4 minute distal spines. 8th joint: d- and e-bristles longer than b-bristle, bare with blunt tips; f- and g-bristles similar to c-bristle. (Note: left limb of USNM 193868 with additional bristle similar in length and type to d-bristle but with base lateral to bases of d-and e-bristles and adjacent to f-bristle; the additional bristle not observed on right limb, nor on USNM 193834, and probably its presence is an aberrancy.)

Second Antenna: Protopodite bare. Endopodite 2-jointed: 1st joint with 3 small bare proximal bristles; 2nd joint with long stout spinous bristle. Exopodite: joint 1 with small recurved medial terminal bristle; bristles of joints 2-8 with few natatory hairs; 9th joint with 2 bristles (1 long with natatory hairs, 1 short with short spines); joints 2-7 with minute spines forming row along distal edges.

Mandible: Coxale endite bifurcate, with few stout spines, and with long hairs at base. Ventral margin of coxale with long spines. Basale: dorsal margin with 1 bristle near midlength and 2 subterminal; ventral margin with 7 or 8 bristles (including 2 or 3 short bristles in lateral row). Exopodite small with blunt tip and subterminal bristle. Endopodite: 1st joint: medial side with distal spines and 2 small spine-like bristles at base of slender ventral claw; 2nd joint with 2 subterminal spine-like bristles on dorsal margin and 1 small spine-like lateral bristle near base of slender ventral claw; 3rd joint with 3 small spinelike bristles (2 ventral, 1 dorsal) at base of slender terminal claw.

Maxilla: Coxale with spinous dorsal bristle. Endite I with 6 bristles; endite II with 5 bristles; endite HI with 6 bristles. Basale with bare medial bristle some distance from exopodite. Exopodite with 3 bristles (1 long, 2 short). Endopodite: 1st joint with spinous alpha- and beta-bristle; 2nd joint with 2 fairly long spinous a-bristies, 1 spinous c-bristle, and 5 pectinate end bristles.

Fifth Limb: Epipodite with 40 or 41 plumose bristles. Endite with 1 small bare bristle. Exopodite: 1st joint with 3 spinous bristles; 2nd joint with 4 or 5 long spinous terminal bristles, and 1 short bare bristle near inner lobe of 3rd joint; 3rd joint with 4 spinous bristles (3 on inner and 1 on outer lobe); fused 4th and 5th joints with total of 4 spinous bristles. Joints 1 and 2 hirsute.

Sixth Limb: With 4 endites: endite I with 2 small bristles (1 with few indistinct spines, other bare); endite II with 2 long spinous bristles; endite III with 4 spinous bristles; endite IV with 2 or 3 spinous bristles. End joint with 2 spinous anterior bristles, 1 spinous bristle at midwidth, and 2 plumose posterior bristles. Posterior half of limb hirsute.

Seventh Limb: Proximal group with 4 bristles, 2 on each side, each with 3 bells; terminal group with 6 bristles, 3 on each side, each with 2-4 bells. Terminus with opposing combs each with 9-11 teeth.

Furca: Each lamella with 7 or 8 claws; claw 1 nonarticulated; claw 3 1/2 to 3/4 length of claw 4; right lamella anterior to left by width of base of claw 1. Right lamella of USNM 193868 differs in having only 6 claws and in 3rd claw being longer than 4th.

Bellonci Organ: 1-jointed, elongate with rounded tip.

Eyes: Lateral eyes absent. Medial eye bare, unpigmented.

Upper Lip: Evenly rounded with few hairs on anterior corner.

Genitalia and Brush-like Organ: Oval genitalia with attached spermatophore on each side of body anterior to furca. Several small ringed bristles near genitalia.

Anterior of Body: Each mandibular socket dorsal to lip with anterior prong.

Posterior of Body: Long hairs at midheight.

Y-Sclerite: Without ventral branch.

Number of Eggs: USNM 193868 with 4 eggs in marsupium and 5 smaller unextruded eggs; length of typical extruded egg 0.37 mm; length of typical unextruded egg 0.26 mm. Specimen from Slope 32 with 5 eggs in marsupium.

DESCRIPTION OF ADULT MALE.—Carapace more elongate than that of female, with prominent rostrum and shallow incisur; carapace highest just anterior to midlength and widest at about midlength.

Ornamentation: Similar to that of adult female.

Infold: Not examined.

Central Adductor Muscle Attachments: Similar to those of adult female.

Carapace Size (length, height in mm): USNM 193945, 1.78, 1.17.

First Antenna: 1st joint bare. 2nd joint with rows of minute medial and lateral spines, and 1 ringed dorsal bristle with long proximal and short distal spines (bristle missing on illustrated left limb so bristle of right limb shown in its place dashed). 3rd joint fused to 4th, with 2 long ringed bristles (1 ventral, 1 dorsal) with short spines. 4th joint with 3 ringed bristles (2 ventral, 1 dorsal) with short spines. 5th joint triangular and placed ventrally between 4th and 6th joints, with basal part with abundant filaments and 1 long stout ringed bristle with 4 marginal filaments and bifurcate tip. 6th joint with short ringed bare medial bristle. 7th joint: a-bristle with short marginal spines; b-bristle long, with 2 marginal filaments and undivided tip; c-bristle longer than b-bristle, reaching slightly past stout bristle of 5th joint, with 6 marginal filaments and bifurcate tip. 8th joint: d-and e-bristles about same length as b-bristle, bare with blunt tips; f-bristle slightly longer than b-bristle, with 5 filaments and bifurcate tip; g-bristle stouter and longer than f-bristle, with 6 filaments and bifurcate tip.

Second Antenna: Protopodite bare. Endopodite 3-jointed: 1st joint with 3 small bare proximal bristles and 4 distal rows of medial spines; 2nd joint elongate, with 3 bare proximal bristles; 3rd joint recurved, with 2 small bare bristles and about 11 ridges at tip. Exopodite: 1st joint with small recurved medial terminal bristle; bristles of joints 2-8 with natatory hairs, no spines; 9th joint with 2 bristles (1 long with natatory hairs, 1 short with small hair-like spines); joints 2-8 with minute spines forming row along distal edges.

Mandible: Coxale endite represented by 2 spines; coxale with long distal lateral spines in cluster at midheight (these could be on basale) (not shown). Basale: ventral margin with 1 long spinous ringed bristle (broken on both limbs of USNM 194945) and 7 shorter spinous ringed bristles (4 short with bases on medial side, 3 longer with bases on lateral side); dorsal margin with 3 short bare ringed distal bristles; medial surface with long proximal spines near dorsal margin. Exopodite 2-jointed (unusual), about 1/3 length of dorsal margin of 1st endopodial joint, with suture near midlength, rounded tip with indistinct hairs, and bare ringed bristle with base at suture. Endopodite: 1st joint with proximal indentation in dorsal margin adjacent to exopodite, distal rows of medial spines, and 3 subterminal ventral bristles (1 long with long proximal and short distal spines, 2 short with short spines); 2nd joint with rows of medial spines, 2 spinous ringed dorsal bristles at midlength, and 2 spinous ringed terminal ventral bristles; 3rd endopodial joint with 1 small dorsal weakly-ringed a-bristle, 1 long claw-like b-bristle with short ventral spines (bristle broken off on illustrated left limb on which right claw of right limb is shown dashed; claw of right limb with tip broken off), 1 short ringed c-bristle with short ventral spines, and 1 longer bare ringed d-bristle. (Lettering of bristles of 3rd endopodial joint from Komicker, 1969:27.)

Maxilla: Limb reduced. Precoxale, coxale and basale with dorsal fringe of long hairs. Coxale with plumose ringed dorsal bristle. Endites I, II, and III small with weakly developed plumose ringed bristles (bristles not shown). Basale with short ringed bristle near exopodite and numerous lateral hairs. Exopodite with 3 well-developed ringed bristles (1 long, 2 shorter). Endopodite: 1st joint with abundant lateral hairs, few rows of minute lateral spines, and a plumose alpha-and beta-bristle; 2nd joint with rows of lateral spines, 2 well-developed ringed bristles with small spines (may be a-bristles), 1 plumose ringed medial bristle (may be c-bristle) and 5 plumose weakly developed plumose ringed terminal bristles). (Rings of most bristles not shown.)

Fifth Limb: Limb reduced. Epipodite of illustrated limb with small part broken off, with 32 bristles on remaining part (only 2 shown). Single endite with short ringed bristle with long proximal and short distal hairs. Exopodite: 1st joint with 3 ringed bristles with long proximal and short distal hairs. 2nd and 3rd joints fused; 2nd joint with 4 plumose ringed bristles and distal hirsute lobe bearing short plumose ringed bristle; inner lobe of 3rd joint with 4 plumose ringed bristles (1 bristle close to 2nd joint); outer lobe of 3rd joint with 1 ringed bristle with few indistinct small spines. 4th and 5th joints fused, with total of 3 plumose ringed bristles. (Rings not shown on all bristles.)

Sixth Limb: Interpreted as having 4 endites: endite I with 3 ringed bristles (2 small with short spines, 1 longer with long proximal and short distal hairs); endite II with 2 ringed bristles (1 long with long proximal hairs, 1 short with long proximal and short distal spines); endite III with 4 ringed bristles (3 long with long marginal spines, 1 short with long proximal and short distal spines); endite IV separated from end joint by shallow concavity, with 3 ringed bristles (2 long with long spines, 1 shorter with long proximal and short distal spines). End joint with 3 or 4 spinous anterior bristles, 2 spinous bristles at midwidth, and 2 plumose posterior bristles, all bristles ringed. Limb hirsute. (Rings of bristles not shown.)

Seventh Limb: Proximal group with 4 bristles, 2 on each side, each with 2 bells; terminal group with 4 bristles, 2 on each side, each with 3 bells. Terminus with opposing combs, each with 6-8 teeth.

Furca: Each lamella with 7 claws; claw 1 nonarticulated; claw 3 about half length of claw 4.

Bellonci Organ: 1-jointed, elongate, broadening distally, with rounded tip with minute processes.

Eyes: Lateral eyes absent Medial eye bare, unpigmented.

Genitalia: Elliptical paired seminal vesicles appearing brownish red in both transmitted and reflected light, with small distinctly red part at anterior end. A complex copulatory organ of 3 lobes at each side of body, all with small ringed bristles; main lobe with elongate sclerotized hook-like clasper.

Posterior of Body: Evenly rounded, bare.

Y-Sclerite: Without ventral branch.

COMPARISONS.—The Y-sclerite of previously described species of Sarsiellinae on which it is known have a distal ventral branch. The ventral branch is absent on S. rex. The Y-sclerite is known for only 3 previously described species of Spinacopia (S. menziesi (Kornicker, 1969, fig. Ae; 1975, fig. 362g), S. octo (Komicker, 1975, fig. 432c), S. variabilis (Komicker, 1969, fig. 6n)), and 6 new species described herein; all except S. rex have a ventral branch. In the key to species of Spinacopia in Kornicker (1975:584), specimens referred to S. rex herein run down to S. variabilis, a species having a ventral branch on the Y-sclerite but otherwise very similar to S. rex.”

(Kornicker, 1995, pp. 43-49)