Cylindroleberis vix Kornicker 1992

Cylindroleberis vix Kornicker, 1992

Cylindroleberis vix Kornicker, 1992:179, figs. 106–109.

HOLOTYPE.—MNHN Os 467, undissected ovigerous female in alcohol.

TYPE LOCALITY.—Mozambique Channel, Mayotte, depth 15–20 m (Kornicker, 1992:179).

MATERIAL.—BT-615: USNM 194193, ovigerous female with body removed from shell. BT-693: USNM 194197, juvenile. BT-706: USNM 194190, 2 ovigerous females, 1 adult male, and 3 additional specimens. BT-709: USNM 194183, partly dissected ovigerous female; USNM 194184, adult male on slide and in alcohol; USNM 194188, adult female, 2 ovigerous females, and 6 additional specimens (mostly juveniles). BT-712: USNM 194191, ovigerous female, juvenile, and 1 empty carapace. BT-715: USNM 194192, adult female. BT-773: USNM 194194, ovigerous female. BT-779: USNM 194195, partly dissected ovigerous female. BT-811: USNM 194189, adult male with body removed from shell. BT-836: USNM 194196, adult male plus adult female.

DISTRIBUTION.—Mozambique Channel at depths of 6–20 m (Kornicker, 1992:179). Madagascar: see “Material.”

DISTRIBUTION.—Members of the genus are cosmopolitan between latitudes of about 53°N and 65°S with a depth range of intertidal to 4303 m (Kornicker and Caraion, 1974:7). Species have not been reported previously from the western Indian Ocean, but seven species have been reported off the western coast of Africa (Kornicker, 1976:11).

Cylindroleberis vix

ETYMOLOGY.—From the Latin vix (with difficulty, barely).

HOLOTYPE.—MNHN Os 467, undissected ovigerous female in alcohol.

TYPE LOCALITY.—Sta 32-S, 25 Mar 1977, N Pamanzi Island, Mayotte, 12°45′06″S, 45°17′54″E, depth 15–20 m.

PARATYPES.—Sta 23-S: Paris, 1 ovigerous female and 1 early instar in alcohol. Sta 32-S: USNM 193751, 1 adult female in alcohol; USNM 193752, 1 adult female on slide and in alcohol; Paris, 1 A-1 instar in alcohol, 1 A-2 instar in alcohol, and 1 early instar in alcohol (length 1.24 mm, height 0.52 mm; height 42% of length).

DISTRIBUTION.—Sta 23-S, Vatou Islet, Mayotte, depth 6 m. Sta 32-S, N Pamanzi Island, Mayotte, depth 15–20 m. Known depth range 6–20 m.

DESCRIPTION OF ADULT FEMALE (Figures 106–109).—Carapace elongate with parallel straight dorsal and ventral margins, in lateral view anterior and posterior margins evenly rounded (Figure 106a,e,m,n); outer surface with abundant minute pores; a few widely separated slender bristles present along inner side of shell just proximal to ventral margin and distal to selvage (1 bristle shown in Figure 106f).

Infold: Rostral infold with 10 bristles between list and incisur, and about 24 long and 20 short bristles dorsal to list (Figure 107a, not all bristles dorsal to list shown). Broad anteroventral infold with about 25 long and 15 short bristles (Figure 107a, not all bristles shown). Anterior of ventral infold with about 21 short bristles in row ending posteriorly where list broadens and bears flap-like bristles. Narrow list beginning near inner margin of infold just ventral to inner end of incisur, extending along anterior of ventral infold, then broadening and continuing on posterior infold (Figures 106f,m,n, 107b,c). Broad posterior list with 28–33 broad transparent flap-like bristles and about 24 short bristles (not more than 1 short bristle between each pair of flap-like bristles) (Figure 107b,c, not all bristles shown). About 10 long bristles in row on ventral infold between anterior part of broad list and valve edge (Figure 107b,c, only 2 or 3 long bristles shown). 3 scoop-like processes on posterior infold between list and valve edge (Figure 107b,c); several (about 6) tube-like pores present in vicinity of processes (shown as dashed lines). Infold of posterodorsal corner of right valve with small flat triangular process with row of long hairs (Figures 106g, 107c).

Selvage: Selvage set inward from valve edge along ventral and posteroventral shell margins, and on the right valve of USNM 193752, but not on USNM 193751, also set inward from posterior edge (Figure 106f). Selvage medial to valve edge along ventral and posterior shell margins. Selvage with narrow lamellar prolongation (fringed with long marginal hairs) at inner of ventral margin of incisur (Figure 106p). Selvage with narrow lamellar prolongation (fringed with short marginal hairs) along posterior margin just anterior to anterior juncture of hinge. Lamellar prolongation not observed elsewhere. Selvage along ventral margin of shell broad, bearing row of minute pores (Figure 106f).

Central Adductor Muscle Attachments (Figure 106b,c,q): Comprising 14 ovoid individual attachments.

Carapace Size: MNHN Os 467, holotype, length 2.16, height 0.75 mm; height 35% of length. USNM 193751, length 2.17 mm, height 0.79 mm; height 36% of length. USNM 193752, length 2.15 mm, height 0.71 mm; height 33% of length.

First Antenna (Figure 107d–f): 1st joint with medial spines. 2nd joint with proximal cluster of hairs on medial surface, 1 backward curving dorsal bristle with long spines, and 1 shorter distal lateral bristle with short spines. 3rd joint fused to 4th, without medial suture separating them but with indistinct lateral suture on ventral half of joint. Inferred 3rd joint with minute bristle at short ventral margin and 6 spinous bristles (4 single and 2 paired) on long dorsal margin (1st, 2nd, and 4th single bristles and medial of paired bristles with long spines, 3rd single bristle and lateral of paired bristles with short spines). Inferred 4th joint with long ventral and short dorsal margin; dorsal margin with long bristle (with base on medial side) with short marginal spines; ventral margin with 2 slender terminal bristles with short marginal spines; lateral surface with spines at distal ventral corner. Sensory bristle of 5th joint stout, with 1 short proximal filament and 6 long terminal filaments. 6th joint with long medial bristle with short marginal spines. 7th joint: a-bristle claw-like, bare, with blunt tip (wom?); b-bristle about twice length of a-bristle, with 1 short filament at midlength and 3 longer distal marginal filaments; c-bristle about twice length of b-bristle, with 4 or 5 short marginal Filaments. 8th joint: d-bristle absent; e-bristle about same length as b-bristle, bare with blunt tip, minute lateral pore at base (Figure 107f); f-bristle bent dorsally, about same length as b-bristle, with 4 short marginal filaments (filaments and distal half of stem with short spines); g-bristle similar to c-bristle.

Second Antenna: Protopodite bare, without medial bristle. Endopodite distinctly 3-jointed, with terminal filament about same length as stem (Figure 107g). Exopodite: bristle of 2nd joint reaching just past 9th joint, with abundant slender ventral spines (spines thinner on distal half); bristles of joints 3–8 with proximal ventral spines and distal natatory hairs; 9th joint with 4 bristles (2 long with proximal ventral spines and distal natatory hairs, 1 medium and 1 short (dorsal) with slender ventral spines but no natatory hairs); joints 3–8 with basal spines (spines stouter on distal joints; spine of 8th joint about length of 9th joint); 9th joint with lateral spine about same length as spine of 8th joint but broader; joints 2–8 with minute spines forming rows along distal margin.

Mandible: Coxale endite (Figure 108a): 1 small medial bristle near base of ventral branch; ventral branch with 3 oblique rows of spines, tip with 1 fairly long dorsal spine, 1 minute triangular ventral spine, and 1 slender spine between them (detail in Figure 108a). Dorsal branch: distal ventral margin with 2 pairs of triangular backward-pointing teeth followed by 2 or 3 rounded teeth, then short main spine; margin between main spine and tip of branch with small spines; tip with short spine-like prolongation; bristle on dorsal margin of branch with base set back from tip of branch, hirsute, extending well past tip; dorsal margin serrate distally. Basale endite with 4 pectinate end bristles, 3 triaenid bristles with 4 or 5 pairs of marginal spines excluding terminal pair (Figure 108b), 2 bare dwarf bristles (longest 2 or 3 times length of other (Figures 106h, 108c)), glandular peg, and few proximal medial hairs. Basale: medial surface with few hairs near ventral margin; dorsal margin with 1 short bare backward-pointing bristle just distal to midlength (on USNM 193752 bristle projecting outward from margin (Figure 108b); on USNM 193751 bristle not projecting outward, folded back on medial surface of basale (Figure 106i)), and 2 long slender terminal bristles with short marginal hairs; ventral margin either bare or with 1 triaenid bristle (near base of endite) with 4 or 5 pairs of marginal spines excluding terminal pair. Exopodite about length of dorsal margin of 1st endopodial joint, with 2 small bristles (Figure 108d). 1st endopodial joint with 3 long ventral bristles (2 with long spines, 1 with only short spines). 2nd endopodial joint: medial surface with minute spines in rows; ventral margin with 3 long terminal bristles with short marginal spines; dorsal margin with stout a-, b-, c, and d-bristles (d-bristle slightly stouter and with more marginal spines than others), 1 short bare bristle proximal to a-bristle, 1 short spinous cleaning bristle between b- and c-bristles (closer to b-bristle), 6 spinous cleaning bristles forming oblique row on medial surface in vicinity of c- and d-bristles, 1 long slender spinous bristle on medial surface just distal to d-bristle, 1 long spinous bristle on lateral surface with base between c- and d-bristles, and no lateral bristle between b- and c-bristles. 3rd endopodial joint with short stout dorsal claw with rounded tip (worn?), 3 longer spinous stout terminal bristles, 1 long stout spinous bristle with base on lateral surface near dorsal claw, and 1 short spinous bristle with base on medial surface.

Maxilla (Figure 107h): Epipodite not reaching middle of dorsal margin of basale, with hairs at tip. Endite I with 3 long and 1 short bristle. Endite II with 3 long spinous bristles and few long hairs near bases of bristles. Basale: ventral margin with 1 short proximal bristle, 1 small indistinct distal bristle, and 1 long spinous terminal bristle; dorsal margin with distal hairs and 2 small bristles with bases on medial surface (1 proximal, 1 distal); lateral surface with 1 short proximal bristle; medial surface with long distal hairs near ventral margin. Basale and 1st endopodial joint separated by barely visible suture. 1st endopodial joint with short distal alpha-bristle and long spinous beta-bristle. 2nd endopodial joint with long spinous terminal bristle reaching past tip of beta-bristle.

Fifth Limb: Comb elongate with distal ventral bristles much longer than proximal bristles (Figure 108e). Stout exopodial bristle reaching past end of comb (Figure 106j); 2 slender bristles just ventral to base of stout bristle (Figure 108g), 2 pairs of bristles near ventral margin, and 1 bristle with base almost on ventral margin (Figure 108f).

Sixth Limb (Figure 108h): Medial surface with small proximal bristle near vertical muscle bundle. Anterior margin with 2 endites, each with 1 spinous bristle (distal endite with longer bristle). Anterior tip of skirt with 6 spinous bristles; lateral flap with 1 small spinous bristle; posteroventral margin with 31–36 spinous bristles.

Seventh Limb (Figures 106k, 108i): 6 bristles in proximal group (3 on each side) with 3–5 bells; 2 bristles (1 on each side with 4 bells) on segment just proximal to terminus; 4 bristles on terminus (2 on each side, 1 with 3 bells, 1 with 5). Terminus with opposing combs, each with 14–16 spinous teeth.

Furca (Figure 109a,b): Each lamella with 9 claws followed by 1 or 2 bristle-like claws; each claw with spines along anterior and posterior margins; claw 1 of right lamella anterior to claw 1 of left lamella by width of base of claw; posterior claws of lamellae followed by single rounded process with minute spines along posterior edge.

Bellonci Organ (Figures 106l, 109c): Elongate, broadest at midlength, with rounded tip.

Eyes: Medial eye unpigmented, bare (Figures 106l, 109c). Lateral eye larger than medial eye, with about 17 ommatidia and black pigment between ommatidia (Figures 106e, 109d).

Lips (Figure 109c): Upper lip a hirsute lobe on each side of low saddle, without spines on lobes or saddle. Lower lip a hirsute lateral flap on each side of mouth.

Genitalia (Figures 106k, 109a): Small amber-colored oval on each side of body anterior to furca.

Posterior of Body (Figure 109e): A low spinous process at posterodorsal corner dorsal to posterior end of girdle; a 2nd spinous lobe just ventral to posterior end of girdle; posterior margin between 2nd lobe and furca with abundant minute spines.

Y-Sclerite (Figures 106k, 109e): With short ventral branch.

Gills (Figure 106k): 7 long posterior gills on each side of body.

Eggs: MNHN Os 467, holotype with 1 egg in marsupium (maximum length of egg 0.21 mm (Figure 106a,d)). USNM 193752 with many small unextruded eggs (Figure 109e).

DESCRIPTION OF A-2 FEMALE.—Carapace with shape similar to that of adult female.

Carapace Size: Paris, length 1.39 mm, height 0.54 mm; height 39% of length.

First Antenna: Sensory bristle of 5th joint of 1st antenna similar to that of adult female except for lacking short proximal filament.

Second Antenna: 9th joint of exopodite with only 3 bristles, limb otherwise similar to that of adult female.

Seventh Limb: With tapering bristles (2 on segment just proximal to terminus, 4 on terminus; bristles of proximal group not counted).

DESCRIPTION OF A-1 FEMALE.—Carapace with shape similar to that of adult female.

Carapace Size: Paris, length 1.77 mm, height 0.66 mm; height 37% of length.

First Antenna: Sensory bristle of 5th joint of 1st antenna similar to that of adult female.

Second Antenna: 9th joint of exopodite with 4 bristles, similar to that of adult female.

COMPARISONS.—In the key to species of Cylindroleberis in Kornicker (1991:110) the female C. vix keys out as C. bacescui Kornicker and Caraion, 1974, or possibly C. grimaldi Skogsberg, 1920. The carapace of the female C. vix is more elongate than either species (height as percent of length: C. vix 33%–35%, C. bacescui 40%–42% (Kornicker and Caraion, 1974:31), C. grimaldi 45% (Skogsberg, 1920:510)). The carapace length of the female C. vix is 2.15–2.17 mm (3 specimens), longer than other species referred to the genus, which range in length from 1.1 to 1.91 mm (Kornicker, 1991:110). The skirt of the 6th limb of C. vix bears 31–36 posteroventral bristles, compared to 23–26 bristles for C. bacescui (Kornicker and Caraion, 1974:34), and 17–25 for C. grimaldi (Skogsberg, 1920:513).