Cylindroleberis variabilis Kornicker 1970

Cylindroleberis variabilis

HOLOTYPE.—USNM 125625, valves and some appendages in alcohol, remaining appendages on slides, 9 with 6 eggs in marsupium.

PARATYPES.—USNM 125626, adult ; USNM 125627, juvenile , length 0.80 mm (undissected); USNM 125628, juvenile (N–1 stage), length 1.23 mm, height 0.61 mm.

TYPE-LOCALITY.—Station M–10, Sacol Island, Zamboanga Province, Philippines, Lat. 06°56′ N, Long. 122°11′ E, water depth 1–2 m, sandy mud flat near mangrove area, corals abundant. USNM 125626 and 125627 from same sample as holotype.

OTHER LOCALITIES.—USNM 125628 from Station M–13, Cang-Alwang, Eiquijor Island, Negros Province, Philippines, Lat. 09° 13′ N, Long. 123°30′ E, reef flat, water depth 1–3 m.

ETYMOLOGY.—The specific name “variabilis” refers to the variability in the number of midbristles on the dorsal margin of the basale of the mandible and in the number of dwarf bristles on the basale endite of the mandible.

DESCRIPTION OF FEMALE.—Carapace elongate with smooth surface and scattered minute pores and hairs (Figure 3a–c); anterior rounded with deep incisur slightly below valve middle; posterior rounded without caudal process.

Infold: Infold behind anterior margin broad with numerous bristles (Figure 13f). Posterior and posteroventral infold broad with list along inner margin bearing about 24 transparent flap-like bristles and 10 small bristles; approximately 6 transparent flap-like bristles present between posterior list and posterior margin of valve (Figure 13g). Ventral and posteroventral infold with about 15 bristles between ventral edge of valve and inner margin of infold; posterior 5 or 6 of the 15 longer than others (Figure 13h).

Size: Holotype, USNM 125625, length 1.37 mm, height 0.64 mm, height as percent of length 46; USNM 125626, length, 1.40 mm, height 0.62 mm, height as percent of length 44.

First antenna: Medial surface of 1st and 2nd joints hirsute; 2nd joint with short distolateral bristle and spinous dorsal subterminal bristle; 3rd joint with short bare ventral bristle and 6 long dorsal bristles, all with short or long spines; 3rd and 4th joint not separated by distinct suture except near ventral and dorsal margins; 4th joint with long dorsal bristle with short marginal spines and 1 long and 1 short distoventral bristle (Figure 13i); sensory bristle with short proximal dorsal filament and 6 long terminal filaments; medial bristle of 6th joint with short marginal spines; a-claw bare except for few broad vague teeth along distoventral margin; -8th joint without d-bristle and with bare e-bristle; f-bristle at right angles to stem, with 5 interior spinose filaments and spines along distal anterior margin.

Second antenna: Protopodite with neither medial bristle nor marginal spines. Endopodite 3-jointed with terminal bristle about twice length of stem (Figure 13l). Exopodite: bristle of 2nd joint with numerous short slender ventral spines (Figure 13k); bristles of joints 3 to 8 with proximal ventral spines and natatory hairs; 9th joint with 4 bristles, 2 short, 2 long with proximal ventral spines and natatory hairs; joints 4 to 9 with basal spines (Figure 13j).

Mandible (Figure 13m): Tip of ventral branch of coxale endite with 2 stout teeth; small bristle present on dorsal branch near base of ventral branch (Figure 13n). Basale endite with glandular peg, 4 spinous end bristles and 3 triaenid bristles with 2 to 3 pairs of marginal spines; 1–2 dwarf bristles present at base of endite; 1 short tapered bristle present proximal to U-shaped glandular opening near ventral margin of basale (bristle triaenid type on paratype); dorsal margin of basale with 0 to 1 short bare midbristle and 2 long terminal bristles (holotype with midbristle on left mandible and none on right; paratype without midbristle). Exopodite short with 2 small subterminal bristles. Endopodite: 1st joint with 3 long spinous ventral bristles; ventral margin of 2nd joint with 1 medium and 2 long terminal bristles, all with spines; dorsal margin of 2nd joint with 1 short proximal bristle and stout a-, b-, c-, d-bristles, c-bristle stouter than others, d-bristle with marginal spines; short spinous bristle present between b- and c-bristles; medial surface with 5 spinous bristles forming row near base of c-bristle; 1 short bristle present on medial side near base of d-bristle; 1 long spinous bristle present on lateral side near base of c-bristle. End joint with short dorsal claw with small spines along ventral margin, 3 stout bristles and 2 slender bristles, all with marginal spines (see Table 5).

Maxilla (Figure 14a): First endite with 3 long and 1 short bristle; 2nd endite with 3 long bristles; epipodial appendage rather short and with hirsute tip; dorsal margin of basale hirsute, with short proximal and distal bristle; ventral margin of basale with short proximal bristle and long spinous terminal bristle. Endopodite: 1st joint with minute bare anterior bristle and long bare beta-bristle; end joint with bare terminal bristle slightly longer than beta-bristle.

Fifth limb: Lateral surface of comb with long spinose bristle, 2 short bristles near base of long bristle and 4 short bristles near ventral margin (Figure 14b); distal bristle but one longer than others.

Sixth limb (Figure 14c, d): Upper bristle of anterior margin slender with few faint marginal spines; lower bristle fairly stout, spinous. Anteroventral margin with 4 spinous bristles; posteroventral margin with 16 spinous bristles; posteroventral corner evenly rounded; anterior, posterior, anteroventral margins including lateral flap, hirsute; medial surface proximal to horizontal bar with spines forming clusters.

Seventh limb: Twelve bristles present: 6 in distal group, 3 on each side; 6 in proximal group, 3 on each side; each bristle with 3 to 5 bells. Terminus with opposing combs, each comb with about 15 spinous teeth.

Furca (Figure 14e, f): Each lamella with 10 claws, posterior 2 or 3 secondary; primary claws pectinate along posterior margin, few larger teeth being separated by series of smaller teeth; most claws with slender distal spines along anterior margin; claw 1 with 6–8 minute proximal teeth along posterior margin. Claw 1 of right lamella more slender than claw 2, but on left lamella both claws same width. Fused posterior margin of lamellae forming ventral process, ornamented with short spines.

Medial eye and rod-shaped organ (Figure 14h): Medial eye large pigmented. Rod-shaped organ weakly 2-jointed, broadest near middle, rounded at tip.

Lateral eye (Figure 14h): Eye well developed with numerous ommatophores.

Upper lip (Figure 14h): Rounded with ventral hairs; a posterior flap with hirsute margin present on each side.

Brush-like organ (Figure 14g): Organ consisting of about 8 minute bristles dorsal to genitalia.

Genitalia (Figure 14f, g): Consisting of U-shaped sclerotized process, 1 on each side.

Posterior (Figure 14f): Dorsum rounded, hirsute.

COMPARISONS.—Cylindroleberis variabilis, new species, resembles Cylindroleberis grimaldi (Skogsberg, 1920), Cylindroleberis grimaldi vicina (Skogsberg, 1920), and Cylindroleberis nodulifera (Poulsen, 1965). Its carapace differs in having large transparent flap-like bristles on the infold between the list and posterior margin of each valve. C. grimaldi, C. grimaldi vicina, and C. nodulifera have only broad pores in that location. C. variabilis also has only 4 anteroventral bristles on the 6th limb compared to 7 on C. grimaldi and C. grimaldi vicina. C. variabilis also differs from C. nodulifera in not having a node on the 5th joint of the 1st antenna and in having 4 bristles on the 1st endite of the maxilla.

Cylindroleberis variabilis Kornicker, 1970

Cylindroleberis variabilis Kornicker, 1970b:19, figs. 13, 14.

Cylindroleberis sp. Kornicker, 1987b:217.

HOLOTYPE.—USNM 125625, adult female on 3 slides and in alcohol.

TYPE LOCALITY.—Sacol Island, Zamboanga Province, Philippines.

MATERIAL.—Enewetak lagoon: Plankton trap 7, night, coral rubble substrate: USNM 158320, 1 adult male on 2 slides and in alcohol; Composite sample: USNM 158319, 1 A-2 female in alcohol. Midwater trawl off Bokandretok Island: USNM 193633, 1 A-1 female on slide and in alcohol; USNM 193639, 1 adult male in alcohol.

DISTRIBUTION.—Philippine Islands; Enewetak Atoll.

DISTRIBUTION.—Atlantic continental shelf off North America; West Indies; East Indies; and Enewetak Atoll. Known depth range 5–210 m.