Parasterope crinita Kornicker 1975

“Parasterope crinita, new species

Figures 263-266

HOLOTYPE.—USNM 128278, gravid female, length 1.28 mm, carapace and some appendages in alcohol, remaining appendages on slides.

TYPE-LOCALITY.—Eltanin Cruise 16, station 1431, Subantarctic.

ETYMOLOGY.—The specific name "crinita" is derived from the Latin "crinitus" [ = hairy, long haired] and refers to the long hairs and spines on the dorsal margin of the mandibular basale.

PARATYPE.—USNM 128279, 1 juvenile (not dissected), length 0.80 mm, height 0.50 m; from same sample as holotype.

DIAGNOSIS OF ADULT FEMALE.—Carapace tumid, 33 or 34 bristles on infold between list and posterior margin of valve; length 1.28 mm.

Mandible: Dorsal margin of basale without midbristle, but with numerous long hairs and short spines, especially on proximal half; minute bristle present at base of coxale endite.

Maxilla: Dorsal margin of basale with faint hairs and 1 short distal bristle; epipodial appendage hirsute.

Sixth limb: Posteroventral margin with 16-19 bristles.

Seventh limb: With 12 bristles.

Lateral eyes: Well developed with about 16 ommatidia.

DESCRIPTION OF FEMALE.—Carapace tumid, small, greatest height behind valve middle; incisur short, placed below valve middle; ventral and posterior margins rounded; surface smooth, minute punctae visible under high magnification.

Infold: Infold behind rostrum of right valve with 11 bristles on or posterior to list, and 43 fairly long bristles anterior and dorsal to list; in addition to fairly long bristles, numerous minute spines or bristles present (some of these could be remnants of longer bristles); 10 minute bristles present forming row along anterodorsal infold. Infold behind left rostrum with 14 bristles on or behind list and only 21 anterior and dorsal to list, of these, most present in anterodorsal part of list; numerous minute spines also present anterior to list (some could be remnants of longer bristles); 10 minute bristles present forming row along anterodorsal infold. List present starting near inner margin of anterior part of infold, extending along ventral infold and continuing on posterior infold where it broadens; posterior broad list with about 25 broad transparent bristles and about 21 small bristles—about 1 small bristle between each transparent bristle; 33 or 34 bristles present between broad posterior list and posterior margin of valve; about 40 to 50 bristles present along ventral infold between list and ventral margin of valve.

Selvage: Not observed.

Muscle scars: Central muscle scars consisting of about 15 individual scars below valve middle.

Size: USNM 128278, length 1.28 mm, height 0.87 mm.

First antenna: Medial and lateral surfaces of 1st joint spinous. Second joint with long dorsal bristle with long spines along anterior margin, and short lateral bristle with short marginal spines; ventral and dorsal margins with 2 or 3 clusters of spines; lateral surface with row of short spines along distal margin, spines longer in distal dorsal corner. Distinct suture present separating 3rd and 4th joints; 3rd joint with short bare ventral bristle and 6 long spinous dorsal bristles; all dorsal bristles slightly shorter than dorsal bristle of 2nd joint; proximal dorsal bristle stouter than bristle on 2nd joint and remaining dorsal bristles of 3rd joint. Suture separating 4th and 5th joints distinct except for small part near middle of lateral suture; 4th joint with 1 long dorsal bristle with short marginal spines and 2 short ventral bristles, both with short marginal spines; longer of 2 ventral bristles reaching just past distal suture of 5th joint, shorter reaching point on ventral margin of 5th joint about three-fourths from proximal suture; ventral margin of 4th joint with few spines near base of terminal bristles. Sensory bristle of 5th joint with 6 terminal filaments; distal dorsal margin of 5th joint with minute teeth; medial bristle of 6th joint with short marginal spines, and about 3 times length of ventral margin of 6th joint. Seventh joint: a-claw with faint teeth along dorsal margin and near tip on ventral margin; b-bristle slightly longer than a-claw and with 4 or 5 filaments including tip; c-bristle with 6 filaments including tip. Eighth joint: d-bristle missing; e-bristle bare, about length of b-bristle; f-bristle at right angle to stem, with 5 filaments including stem, filaments with short marginal spines; g-bristle with 5 filaments including tip; f- and g-bristles slightly shorter than c-bristle.

Second antenna: Protopodite with small medial bristle, few spines on ventral margin near endopodite, many spines along anterior margin and on anterior half of medial surface. Endopodite short, 3-jointed, joints fairly well defined; 3rd joint with stout terminal bristle broken off near base on holotype. Exopodite: bristle of 2nd joint reaching 9th joint and with slender ventral spines; bristles of joints 3 to 8 with natatory hairs; joints 2 to 8 with short spines forming row along distal margin; joints 3 to 8 with basal spines; joint 9 with lateral spine and 4 bristles, 2 long and 1 medium with natatory hairs, 1 short with short marginal spines; bristles of joints 3 to 7 with marginal spines proximal along ventral margin.

Mandible: Coxale: minute bristle present at base of endite; ventral branch of endite with 3 oblique rows of spines and 2, possibly 3, minute spines on tip; dorsal branch with 4 or 5 low rounded nodes and small main spine; margin between main spine and tip of dorsal branch with bare space followed by coarse and then fine spines; bristle of dorsal margin of dorsal branch missing on left mandible of holotype, but extending past tip of branch on right limb. Basale: end bristles broken on basale endite of holotype; endite with 3 triaenid bristles bearing 3 or 4 pairs of spines plus long terminal pair, small glandular peg and single dwarf bristle; ventral margin of basale near endite with triaenid bristle with 2 pairs of marginal spines; U-shaped process present on margin distal to base of bristle; dorsal margin of basale without midbristle but with numerous long hairs and short spines, especially on proximal half, and 2 long spinous terminal bristles. Exopodite almost reaching distal end of 1st joint of endopodite and with 2 short spinous bristles. Endopodite: 1st joint with 3 long ventral bristles, 1 (the shortest of the 3) with short marginal spines, 2 with long spines (proximal spines shorter than distal spines); ventral margin of 2nd joint with 3 bristles with short marginal spines, middle bristle about one-half length of other bristles and with spines only along inner margin (tip of bristle knifelike); dorsal margin with 1 short spinous proximal bristle and stout a-, b-, c-, and d-bristles; 1 long spinous lateral bristle present between b- and c-bristles and c- and d-bristles; 3 medial spinous cleaning bristles present near base of b-bristle; 6 medial cleaning bristles present near base of c-bristle, all either pectinate or with spines; 1 long spinous medial bristle present at base of d-bristle; medial surface with few spines forming clusters; end joint with dorsal claw and 5 bristles, 4 long, 1 short, all bristles with spines.

Maxilla: Epipodial appendages hirsute; both endites obscure on holotype; basale with 1 proximal bristle below epipodial appendage, 1 short bare distal bristle on dorsal margin; ventral margin with 1 proximal spinous bristle, 1 short bristle near middle, and 1 long spinous terminal bristle; dorsal margin of basale with faint hairs. Endopodite: 1st joint with short bare distal bristle on anterior margin and 1 long 6-bristle with faint spines or bare; 6-bristle almost twice length of endopodite; end joint with long terminal bristle with faint marginal spines, bristle more than twice length of endopodite.

Fifth limb: 2 small bristles present just ventral to base of stout spinous exopodial bristle (it could not be ascertained from holotype whether additional exopodial bristles are present close to ventral margin of comb).

Sixth limb: Medial surface with minute bristle in anterodorsal corner; anterior margin with 1 upper and 1 lower bristle; lateral flap with 2 or 3 faint bristles; anteroventral corner with 2 spinous bristles; left limb of holotype with 16 spinous posteroventral bristles, right limb with 19; medial and lateral surfaces hirsute.

Seventh limb: Proximal and distal groups each with 6 bristles (3+ 3); each bristle with 3 or 4 bells. Terminus consisting of opposing combs, each with 10 or II spinous teeth.

Furca: Each lamella with 9 claws of which posterior 2 are small, brisdelike; claws 1 to 7 with teeth along posterior margin; some main claws with faint hairs along anterior margins.

Rod-shaped organ: Elongate with rounded tip.

Lateral eye: Eyes well developed with about 16 large ommatidia.

Posterior: Posterior hirsute; dorsum forming right angle; no chitinized bars present as on P. pectinata.

Genitalia: Oval sclerotized process on each side. Brushlike organ not observed.

Eggs: USNM 128278 with IS eggs in marsupium.

COMPARISONS.—P. crinita differs from P. longiseta in not having a long midbristle on the dorsal margin of the basale of the maxilla and in having more bristles between the posterior list and posterior shell margin. It is also smaller. The lateral eye of P. crinita bears 16 ommatidia compared to only 3 in the lateral eye of P. micrommata. The presence of hairs and spines on the dorsal margin of the mandibular basale distinguishes this species from P. muelleri (Skogsberg, 1920) and P. quadrata. The presence of hairs and spines on the dorsal margin of the basale and on the epipodial appendage of the maxilla distinguishes the new species from P. skogsbergi Poulsen, 1965. Parasterope pectinata Poulsen, 1965, differs from P. crinita in having fewer bristles on the infold between the list and posterior edge of the shell, no bristle at the base of the coxale endite of the mandible, no hairs and spines on the dorsal margin of the mandible, no marginal spines on the terminal bristle on the ventral margin of the basale of the maxilla, only a few spines present on the anterior margin of the protopodite of the 2nd antenna, 3 chitinous bars along posterior of the body above furca, and in general having many bristles bare that are spinous on P. crinita. Parasterope obesa Poulsen, 1965, has no spines on the anterior margin of the protopodite of the 2nd antenna and no bristle at the base of the coxale endite of the mandible; it also has 1 small bristle near the base of the stout exopodial bristle of the 5th limb where P. crinite has 2. Many bristles that are bare on appendages of P. obesa have spines on P. crinita. Parasterope mckenziei Kornicker, 1970, differs from P. crinite in having 10 furcal claws and much longer ventral bristles on the 4th joint of the 1st antenna.

DISTRIBUTION.—This species was collected at only the type-locality, on the shelf of South Island, New Zealand, at a depth of 51 m.”

(Kornicker, 1975B, p. 421-427)