Prionotoleberis rex Kornicker 1989

Prionotoleberis rex

Prionotoleberis species A.—Kornicker, 1985:410–412.

ETYMOLOGY.—From the Latin regis, rex (king).

HOLOTYPE.—Adult female, length 1.79 mm, in alcohol, MNHN Os 264, Muséum National d'Histoire Naturelle, Paris, France.

TYPE LOCALITY.—BIOGAS VI, R.V. Jean Charcot, Gulf of Biscay, 44°05′12″N, 4°19′24″W, 1913 m, sta 6, sample DS-87, 1 Nov 1974.

PARATYPES.—BIOGAS III, R.V. Jean Charcot, sta 6: sample DS-49, 1 adult female on slide and in alcohol (USNM 193260).

DISTRIBUTION.—Bay of Biscay, 1845–1913 m.

DESCRIPTION OF ADULT FEMALE (Figures 69, 70).—Carapace elongate with parallel ventral and dorsal margins (Figure 69a,b); anterior and posterior margins evenly rounded.

Infold (Figure 69c, d): Rostral infold with numerous (about 100) bristles, mostly long and near edge of valve; broad anteroventral infold with about 50 bristles; 1 small bristle near inner end of incisur; ventral infold between broad anteroventral infold to point opposite ventral edge of broad posteroventral list with about 37 bristles forming row; narrow list with anterior end ventral to incisur, continuing along ventral infold and becoming broader at posteroventral and posterior infold where it bears about 26 flap-like bristles and about 28 small bristles (not more than 1 or 2 small bristles between each pair of flap-like bristles); 6 bristles forming row between ventral part of flap-bearing list and valve edge. Each valve with 3 small processes between dorsal half of broad posterior list and valve margin (Figure 69d).

Selvage: Selvage broad and bearing fringe along ventral margin of incisur; fringe also present in short segment near posterior juncture of right valve; selvage narrow and without fringe along anterior and ventral margins; broad selvage with smooth edge also present along anteroventral list (Figure 69c) and anterior half of ventral list.

Size: USNM 193260, length 1.78 mm, height 0.96 mm; holotype, length 1.79 mm, height 0.96 mm.

First Antenna (Figure 69e): 1st joint with spines forming rows on medial and lateral sides and along dorsal margin. 2nd joint with spines forming rows on medial and lateral sides and along ventral and dorsal margins, and with stout, spinous, subterminal, dorsal bristle, and shorter, bare, lateral bristle near dorsal margin. 3rd and 4th joints forming square and divided by a suture well defined only near ventral margin; short ventral margin of 3rd joint with minute bristle; dorsal margin with 6 spinous bristles. 4th joint with 1 spinous dorsal bristle, 2 ventral bristles, and medial spines forming distal row near dorsal margin and extending onto margin. 5th joint with distal spines forming row on dorsal margin and extending onto medial and lateral sides; additional spines forming row near midlength of dorsal margin and extending onto lateral side; sensory bristle with short proximal filament and 6 terminal filaments. 6th joint with spines forming row at midlength of dorsal margin and extending onto lateral surface; medial bristle spinous and extending past a-bristle of 7th joint. 7th joint: a-bristle claw-like, bare; b-bristle about longer than a-bristle, with 4 marginal filaments excluding stem; c-bristle not quite twice length of b-bristle, with 6 short marginal filaments. 8th joint: d-bristle represented by minute peg; e-bristle slightly longer than b-bristle, bare with blunt tip; f-bristle bent dorsally and longer than b-bristle but shorter than c-bristle with 4 short marginal filaments (proximal 3 with marginal spines); g-bristle almost as long as c-bristle, with 4 short marginal filaments. (Lateral bristle of 2nd joint is actually missing on right limb of illustrated specimen; Figure 69e.) The dashed bristle shown is from left limb and is shown in illustration in order to indicate its closeness to dorsal margin.)

Second Antenna (Figure 69f): Protopodite with small mediodistal bristle and abundant medial spines forming rows on anterior ; spines present along ventral and dorsal margins (ventral spines stouter than others); additional shorter spines forming few medial rows near posterior end at about midheight. Endopodite with 3 well-defined segments; end segment with long terminal filament. Exopodite: long 1st joint with long distal hairs forming cluster near dorsal margin; bristle of 2nd joint reaching 8th joint, with abundant ventral hair-like spines; bristles of joints 3 to 4 or 5 with few minute ventral spines; bristles of joints 3–8 with natatory hairs; 9th joint with 1 long bristle with natatory hairs, 1 short dorsal bristle with small marginal spines, and a somewhat longer bare bristle (about 2 times length of short bristle); joints 2–8 with spines forming row along distal margin but without basal spines; 9th joint with few spines in place of lateral spine.

Mandible (Figure 69g,h): Coxale endite (Figure 69h): ventral branch with spines forming 4 oblique rows; tip with 2 or 3 minute teeth; small medial britle near base of branch; ventral margin of dorsal branch with 2 paired pointed spines followed by several low rounded processes with minute medial spines; main spine (slender with spines along proximal margin) some distance from tip of branch; terminal bristle hirsute, with long proximal ventral spines extending onto ventral edge of branch; dorsal margin of branch serrate and with hirsute bristle with base set back from tip of branch. Basale endite with 4 end bristles, 3 triaenid bristles with 5 pairs of stout marginal spines proximal to terminal pair and 3–6 pairs of more slender spines proximal to stouter spines, 2 small dwarf bristles (distal bristle stouter and slightly longer), and glandular peg. Basale: ventral margin near base of endite and proximal to U-shaped depression with very small triaenid bristle with 2 pairs of spines proximal to terminal pair, dorsal margin with fairly short bristle (with few distal hairs) at midlength and 2 terminal bristles; long spines present on lateral surface near ventral margin and extending onto margin; fewer spines on medial side near ventral margin; additional lateral spines near dorsal margin. Exopodite with hirsute tip reaching to about midlength of dorsal margin of 1st endopodial joint, with 2 small terminal bristles. 1st endopodial joint with 3 ventral bristles. 2nd endopodial joint: ventral margin with 3 stout spinous terminal bristles; dorsal margin with 2 small proximal bristles and stout spinous a-, b-, c-, and d-bristles; lateral surface with stout spinous bristle between c- and d-bristles but none between b-and c-bristles; medial surface with spines forming rows, 1 or 2 cleaning bristles between a- and b-bristles, 1 or 2 cleaning bristles between b- and c-bristles, 5 cleaning bristles forming oblique row between c- and d-bristles, and 1 stout spinous bristle with base just distal to d-bristle. End joint with dorsal claw with few indistinct distal dorsal teeth, and 5 bristles.

Maxilla (Figure 70a): Epipodite hirsute, tip not reaching midlength of dorsal margin of basale. Endite I with 4 bristles (3 long, 1 short); endite II with 3 long bristles. Basale spinous: medial surface near dorsal margin with 1 short proximal bristle and 1 slightly longer distal bristle; lateral surface with 1 short proximal bristle; ventral margin with 2 paired proximal bristles (only 1 bristle on illustrated left limb, but 2 on right limb of specimen, and holotype with paired bristles on both limbs), 1 minute distal bristle, and 1 long spinous terminal bristle. 1st endopodial joint with small anterior bristle and long beta-bristle. End joint with long terminal bristle slightly longer than beta-bristle of 1st joint.

Fifth Limb (Figure 70b): Lateral side of comb with 1 long stout hirsute exopodial bristle reaching past end of comb, 1 slender bristle just ventral to base of stout bristle, 2 pairs of bristles closer to ventral margin, 4 slender bristles almost on ventral margin (1 proximal, 1 just proximal to proximal paired bristles, and 2 near distal end of comb).

Sixth Limb (Figure 70c): Anterodorsal corner with small medial bristle; anterior margin of trunk with upper and lower spinous bristle at each well-defined endite suture; lower bristle slightly longer than upper. Skirt lateral flap with 1 slender hirsute bristle; anterior end with 4 short spinous bristles; ventral and posteroventral margin with 19 or 20 hirsute bristles (posterior 3 longer); limb hirsute.

Seventh Limb (Figure 70d): Each limb with 12–15 bristles: 5 or 6 in distal group (2 or 3 on each side), 7–9 in proximal group (3–5 on each side); each bristle with 1–3 bells. Terminus with opposing combs, each with 8 spinous teeth.

Furca (Figure 70e): Each lamella with 8 claws; posterior 2 claws bristle-like; posterior claw bent dorsally; claws 1–4 with few long teeth among short teeth along concave margin; claw 1 of right lamella anterior to claw 1 of left lamella; small spinous process present posterior to lamellae.

Bellonci Organ (Figure 70f): Elongate with suture near middle and with rounded tip.

Eyes (Figure 70f): Medial eye unpigmented bare. Lateral eyes absent.

Upper Lip (Figure 70f): Each lobe with 1 or 2 minute anterior spines, and extending ventrally some distance from ventral edge of saddle separating lobes. Lower lip consisting of lateral flap on each side of mouth.

Anterior of Body (Figure 70f): USNM 199260 with anterior hirsute bulge at midheight (just ventral to base of 1st antenna) and 4 minute anterior spines between bulge and upper lip.

Posterior of Body (Figure 70e): With spines at midheight and on evenly rounded posterodorsal corner.

Genitalia (Figure 70e): Consisting of sclerotized ring on each side of body anterior to furca.

Y-Sclerite (Figure 70e): Typical for subfamily.

Gill-like Structures (Figure 70e): Well developed, 7 on each side of body.

Parasites: Holotype with female choniostomatid copepod inside carapace.

COMPARISONS.—The new species differs from P. pax and P. gyion in not having lateral eyes. The maxilla of P. rex differs from that of P. pax in having only 2 bristles rather than 6 on the dorsal margin of the basale, and from that of P. gyion in not having 1 or 2 small bristles on endite II and in having 2 instead of 3 dorsal bristles on the basale. The maxilla of P. rex differs from both species in having paired proximal bristles on the ventral margin of the basale.

Domromeus, new genus

ETYMOLOGY.—The genus is named for Dom R. Rome. Gender masculine.

TYPE SPECIES.—Domromeus heptathrix Kornicker, new species.

DISTRIBUTION.—Known only from in and west of the Bay of Biscay.

COMPOSITION.—The genus is proposed for the new species described herein, Domromeus heptathrix.

DIAGNOSIS (based only on type species).—Female carapace short, ovoid with length less than 2 mm; posterior infold without linear ridge between broad list and posterior valve margin.

First Antenna: Dorsal margin of 3rd joint with fewer than 6 bristles (female of D. heptathrix with 3 or 4 (usually 4) bristles). Sensory bristle of 5th joint with 7 terminal filaments and without small proximal filament. The d-bristle of 8th joint almost as long as e-bristle.

Second Antenna: Protopodite with small medial bristle. Endopodite of female 3-jointed with long terminal filament. Exopodite: with basal spines; 9th joint with 2 bristles.

Mandible: Ventral branch of coxale endite with 3 small teeth (inner tooth smaller than others). Basale endite with glandular peg, 4 end bristles, 2 dwarf bristles, and 2 triaenid bristles with about 9 pairs of small spines (distal pairs longer than others) excluding terminal pair; dorsal margin of female basale without midbristle. Exopodite reaching midlength of dorsal margin of 1st endopodial joint. Endopodite: 2nd joint with long lateral bristle between b- and c-bristles of dorsal margin and with relatively few (8) cleaning bristles.

Maxilla: 2nd endopodial joint with single terminal bristle.

Fifth limb: Comb with parallel ventral and dorsal margins; lateral surface with spinous exopodial bristle reaching past end of comb, 2 slender bristles just ventral to base of spinous bristle and 5 bristles near ventral margin of comb.

Sixth Limb: Anterior margin with 1 bristle at upper endite and without bristle at lower endite.

Seventh Limb: Each limb with 6 or 7 bristles; terminus with opposing combs, each with 5 spinous teeth.

Furca: Each lamella with 8 claws.

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

Eyes: Medial eye bare. Lateral eyes absent.

COMPARISONS.—The new genus is defined mainly on the female having a 1st antenna with a well-developed, filament-like, d-bristle, and 7 terminal filaments on the sensory bristle of the 5th joint. The type species, D. heptathrix, has only 3 or 4 dorsal bristles on the 3rd joint of the 1st antenna, but whether this is a specific or generic character is unknown at present

Three other genera have a filament-like, well-developed d-bristle on the 1st antenna, Archasterope Poulsen, 1965, Skogsbergiella Kornicker, 1975a, and Empoulsenia Kornicker, 1965, but none have more than 6 terminal filaments on the sensory bristle of the 5th joint of the 1st antenna. The d-bristle of Archasterope is only about half the length of the e-bristle, compared to being just slightly shorter in Domromeus. All species of the other genera have 6 bristles on the dorsal margin of the 3rd endopodial joint of the female compared to only 3 or 4 on D. heptathrix. The infold of the right valve of Domromeus does not have a linear ridge between the list and posterior valve margin as on Skogsbergiella. The maxilla and the 7th limb of Domromeus bear fewer bristles than those limbs on species of Empoulsenia. Members of the genus Bathyleberis Kornicker, 1975, have a well-developed d-bristle, but it tapers to a point (bristle-like), and on some species bears marginal spines.