Parasterope mauritania Kornicker & Caraion 1974

Parasterope mauritania

HOLOTYPE.—[USNM 139860], ovigerous female, length 1.35 mm. Right valve and some appendages in alcohol; left valve and remaining appendages on slides. Deposited in Museum of Natural History “Grigore Antipa,” Bucharest, Romania.

TYPE-LOCALITY.—Station X041.

PARATYPES.—USNM 141102, 1 juvenile male, deposited in NMNH; [USNM 141103], 1 juvenile male deposited in Museum of Natural History “Gigore Antipa,” Bucharest; USNM 141104, 3 juveniles deposited in NMNH. Paratypes from same sample as holotype.

ADDITIONAL SPECIMENS.—USNM 141825, 1 adult female, length 1.41 mm, height 0.65 mm, height 46 percent of length; USNM 141826, 1 A-l male, length 1.32 mm, height 0.60 mm, height 45 percent of length (3 copepodids in carapace); USNM 141827, 1 A-l male, length 1.36 mm, height 0.65 mm, height 48 percent of length, USNM 141825, 141826 from Thalassa station X068; USNM 141827 from Thalassa station X057.

DISTRIBUTION.—Collected at three stations off Mauritania at depths of 52–96 m (Figures 2, 3).

DESCRIPTION OF FEMALE (Figures 8, 9a–o). — [USNM 139860] with 21–23 hyaline spines on broad list on posterior infold, and 17 long bristles between broad list and posterior margin of valve (Figures 8, 9b). Size: length 1.35 mm, height 0.64 mm, height 47.4 percent of length. Carapace otherwise similar to that of P. aberrata described by Skogsberg (1920:504).

First antenna (Figure 9c): Longer of 2 ventral bristles on 4th joint just reaching distal margin of 6th joint. Limb otherwise similar to that of P. aberrata described by Skogsberg (1920:506).

Second antenna (Figure 9d–f): Endopodite: terminal bristle on endopodite 2.50–2.75 times length of stem; 2nd and 3rd joints fused, but presence of 3rd joint indicated by slight change in outline at usual position of suture on other species. Protopodite with few spines forming clusters along anterodorsal margin. Exopodite with long hairs forming cluster distally on dorsal margin of 1st joint. Limb otherwise as described for P. aberrata by Skogsberg (1920:506).

Mandible (Figure 9g): Coxale endite with small bristle near base of ventral branch. Basale endite with 4 end bristles (1 of these quite short), 2 triaenid bristles with about 9 pairs of marginal spines excluding terminal pair, reduced glandular peg, and 2 subequal dwarf bristles. Endopodite: medial surface of 2nd joint with 1 short cleaning bristle between b- and c-bristles, but closer to b-bristle, 4 cleaning bristles forming row with longest bristle just proximal o c-bristle, and minute spines forming 2 short rows (about 5 to 8 spines in each row) near middle of dorsal half of surface. Limb otherwise as described for P. aberrata by Skogsberg (1920:506).

Maxilla (Figure 9h,i): Epipodial appendage short, faintly hirsute. Basale hirsute; medial surface with 1 short proximal bristle and 1 longer bristle near tip of epipodite, both bristles near dorsal margin; lateral surface with 1 short proximal bristle; ventral margin with 1 backward pointing proximal bristle. Endopodite similar to limb of P. aberrata described by Skogsherg (1920:508).

Fifth limb (Figure 9j): Epipodial appendage with about 53 bristles. Lateral surface of comb with 1 bristle just ventral to base of stout exopodial bristle and 5 bristles near ventral margin.

Sixth limb (Figure 9k,l): Medial surface with minute bristle in proximal anterior corner. Liml otherwise like limb of P. aberrata described b) Skogsberg (1920:508).

Seventh limb, furca, rod-shaped organ, and medial eye (Figure 9m): Similar to limbs of P. aberrata described by Skogsberg (1920:508).

Lateral eye: About same size as medial eye, pigmented, with 12–13 ommatidia.

Upper lip: Each lobe with 2 medial spines (Figure 9o).

Posterior: Dorsum consisting of short process with spines; posterior with short hairs along margin (Figure 9n).

Eggs: [ USNM 139860] with 4 eggs in marsupium.

DESCRIPTION OF JUVENILE MALE (Figure 9p–u). — Shape in lateral view similar to adult female except for more acuminate posterodorsal margin. Size: USNM 141102, length 1.37 mm, height 0.65 mm, [USNM 141103], length 1.45 mm, height 0.69 mm USNM 141826, length 1.32 mm, height 0.60 mm

First antenna: Sensory bristle of 5th limb similar to that of adult female.

Second antenna (Figure 9q,u): Endopodite 3 jointed with long proximal filament on 3rd joint; 9th joint of exopodite with 4 bristles.

Mandible, maxilla (Figure 9r), 5th limb, posterior, rod-shaped organ, and medial eye: similar to those organs on adult female.

Sixth limb: Limbs of USNM 141102 and [USNM 141103] with no posteroventral bristles, limbs of USNM 141826 with 1 short bristle in middle of ventral margin.

Seventh limb: Similar to adult female except short bristles tapering distally on both specimens examined. Long bristles also tapering on smaller specimen.

Furca: Similar except possibly with one less claw (not examined in detail).

Lateral eye (Figure 9s): Larger than on female, with about 20 ommatidia.

PARASITES.—Two larval copepods inside the carapace of USNM 141826, a juvenile (A-l) male.

COMPARISONS:.—The 6th limbs of Parasterope aberrata (Skogsberg 1920), P. nana Poulsen, 1965, some specimens of P. corrugata Poulsen, 1965, and the new species, P. mauritania, have no posteroventral bristles on the 6th limb. The basale of the maxilla of P. mauritania bears a single bristle near the dorsal margin opposite the tip of the epipodite. This bristle is not present on P. aberrata. The female carapace of P. mauritania is shorter than that of P. aberrata, 1.35–1.41 mm compared to 1.65–1.71 mm. The carapace of P. nana and P. corrugata differs from that of P. mauritania in lacking processes on the posterior infold.