Scleroconcha gallardoi Kornicker 1971

"Scleroconcha gallardoi new species Fig. 18

Holotype. USNM 125397, valves and some append. ages in alcohol, remaining appendages on slides, female with 27 eggs in brood chamber, length 4.07 mm, height 2.73 mm.

Paratypes. USNM 125398, adult female; USNM 125399, gravid female; USNM 125440, adult female; USNM 125441, N-1 male. In addition, 15 juveniles were returned to Universidad Concepcion, Instituto Central de Biologia, Departamento de Zoologia, Concepcion, Chile.

Type locality. Off Greenwich Island, Station 31, 62° 29.1'S, 59°41.0'W, Jan. 12, 1968, bottom depth 39 meters, sandy mud bottom.

Other localities. Off Greenwich Island: Stations 23, 37, 54, 55, 56. In Bransfield Strait: Station 2.

Etymology. This species is named for its collector, Dr. V. A. Gallardo.

Distribution. The distribution of specimens in the collection is as follows (numerals represent Station—number of specimens) : 2-1, 23-1, 31-1, 37-2, 54-1, 55-2, 56-12.

Description of adult female. Carapace (Figure 18a) identical except for size to Scleroconcha appelloefi (Skogsberg, 1920).

Size: USNM 125397, 9' with 27 eggs in brood chamber, length 4.07 mm, height 2.73 mm; USNM 125398, 9 without eggs, length 3.96 mm, height 2.70 mm; USNM 125340, with 24 eggs in brood cham­ber, length 4.13 mm, height 2.62 mm; USNM 125341, with unextruded eggs, length 4.04 mm, height 2.43 mm. Range of lengths 3.96 mm to 4.13 mm; range of heights 2.43 mm to 2.73 mm.

First antenna: First joint bare; second joint with 3 bristles of which ventral bristle is longest and dorsal bristle shortest, lateral bristle almost reaching middle of fifth joint; third joint with 3 bristles, 1 ventral, 2 dorsal; fourth joint with 4 ventral and 2 dorsal bristles; sensory bristle of fifth joint with 7 proximal and 5 terminal filaments; sixth joint with long, spin­ous medial bristle. Seventh joint: a-bristle spinous, slightly longer than bristle on sixth joint; b-bristle with 2 proximal and 4 terminal filaments; c-bristle with about 5 proximal and 5 terminal filaments. Eighth joint: d- and e-bristles bare, subequal, slightly longer than b-bristle; f-bristle with about 6 proximal and 4 terminal filaments. Joints 2 to 5 with short spines forming clusters along ventral and dorsal mar­gins.

Second antenna: Exopodite: First joint with short medial spines on distal margin; distal margins of joints 2-8 with short spines in row, no basal spine present; bristles of joints 2-4 shorter than length of ex­opodite and without marginal spines or hairs; bristles of joints 5-8 bare or with natatory hairs, distal part broken off; ninth joint with 7 bristles consisting of 4 long and 3 short bristles; long bristles with natatory hairs distally on proximal part and distal part broken off, short bristles with long marginal hairs. Endopo­dite 2-jointed (Figure 18c) : First joint with 6 sub-equal ventral bristles consisting of 5 proximal and 1 distal; medial bristle in proximal group longer than others; second joint with extremely long, spinous ven­tral bristle reaching past ninth joint of exopodite and shorter, bare terminal bristle.

Mandible: Coxale: Short bristle at base of endite; endite spinous with bifurcate tip. Basale: Dorsal mar­gin with 1 long, spinous bristle anterior to middle and 2 terminal; ventral margin with 9 spinous bristles; medial side with 3 pectinate bristles and 2-3 with slender spines. Exopodite ²/₃ length of first endopodite joint and has 2 long, spinous subterminal bristles. Endopodite: Ventral margin of first joint with 3-4 spinous bristles; dorsal margin of second joint with 4­5 bristles in proximal group and 6 spinous bristles in distal group; medial side between groups with short pectinate bristle; ventral margin of second joint with 3-4 spinous bristles in subterminal group and 3 in terminal group; end joint with 3 claws and about 4 bristles; dorsal claw reaching slightly past midpoint of longest claw; all claws with a few proximal teeth along concave margin. Basale and first and second joints of endopodite with marginal spines.

Maxilla: Anterior bristle of basale short and with short marginal spines; first endopodite joint with 5 -beta-bristles. End joint: 1 stout b-bristle present with 4 teeth on concave margin and 3 on convex margin; 2 stout d-bristles present, 1 bare, other with 1 tooth on concave margin.

Fifth limb: Similar to S. appelloefi. Epipodial appendage with 65 bristles.

Sixth limb: First endite with 1 terminal bristle and 2 medial bristles, one medial bristle about ¹/₃ length of other; second endite with 4 bristles, 3 terminal and 1 medial; third endite with 10 bristles, 9 terminal and 1 medial; fourth endite with 9 bristles, 8 terminal and 1 medial; end joint with 35 bristles, 19 marginal and 16 medial (submarginal) ; medial surface of third and fourth endite with few spines forming clusters; medial surface of end joint hirsute. Number of bristles in place of epipodial appendage: USNM 125397 with 4 bristles on one limb and 6 on other; USNM 125440 with 3 bristles on each limb.

Seventh limb: Each limb with 10 bristles; 6 in terminal group, 3 on each side; 4 in proximal group, 2 on each side; each bristle with 3 to 9 bells and marginal spines distally. Comb teeth and pegs with smooth margins; number and attitude of comb teeth and number of pegs on each limb of 4 adult females are shown in the following table (oppos­ing limbs are indicated by 'A' and 'B'):

Number of

Attitude

USNM

Comb Teeth

Number of Pegs

of Comb

Limb A Limb B

Limb A Limb B

125397

16 17

2 1

perpendicular

125398

13 12

1 1

perpendicular

125399

9 9

1 1

parallel

125440

11 11

1 1

parallel

('Parallel' indicates that long axes of comb teeth are oriented parallel to sides of limb; 'perpendicular' indi­cates that comb teeth are oriented perpendicular to sides of limb.)

Furca: Each lamella with 16 claws; claw 3 more slender than claw 4; claw 3 longer than claw 4 on some specimens, shorter on others.

Eyes: Medial eye large, pigmented. Lateral eye elongate with 2 divided ommatophores.

Upper lip and anterior: Anterior with projection near middle; upper lip hirsute.

Eggs: USNM 125397 with 27 eggs in brood cham­ber; USNM 125398 with 24 eggs in brood chamber.

Rod-shaped organ: Elongate, jointed proximally.

Description (part) of juvenile (N-1 stage) male.

Ornamentation of carapace: Similar to adult fe­male.

Size (USNM 125441): Length 3.02 mm, height 2.03 mm.

First antenna: Fourth joint with 3 ventral and 2 dorsal bristles; remaining joints with same number of bristles as on adult female.

Second antenna: Endopodite (3-jointed): First joint with 2 short bristles with few spines; second joint with 1 long proximal ventral bristle with wreaths of long marginal spines, and 6 short distal ventral bristles with short marginal spines; third joint with 1 long, bare dorsal bristle and 2 short, subequal terminal bristles, longest with short marginal spines, other bare. Exopodite: Bristle on second joint with 5 proximal spines; some bristles on ninth joint with short spines, remaining bristles of exopodite bare.

Seventh limb: Each limb with 4 terminal and 4 proximal bristles, each with 2 to 6 bells and marginal spines distally; terminal comb with 3 or 4 smooth teeth oriented perpendicular to margin of limb; 1 smooth peg present opposite comb.

Comparisons. The carapace of S. gallardoi appears identical to that of S. appelloefi except for its larger size. The species may be identified by the number of comb teeth on the seventh limb and by the structure of the teeth margins. Some characteristics of adult fe­males of the two species are compared below:

Characteristic

S. appelloefi

S. gallardoi

Carapace length

3.3-16

3.96-4.13

Seventh limb, number of comb

teeth

7-8

9-17

Seventh limb, margins of comb

teeth

denticulate

smooth

Furca, number of claws

13-15

15-16

Discussion of variability of the comb teeth on the seventh limb. Four adult females are in the collec­tion: USNM 125397 from Station 31, USNM 125398 from Station 2, and USNM 125399 and USNM 125440 from Station 56. The first 2 specimens have 16-17 and 12-13 comb teeth, respectively, and the teeth are oriented with their long axes almost perpendicular to the sides of the limbs. The second 2 specimens have 9 and 11 comb teeth, respectively, and the teeth are oriented with their long axes almost parallel to the sides of the limbs. The difference in orientation between the comb teeth of the first and second pairs of specimens could be interpreted as indicating the pres­ence of 2 species in the collection. The sample from Station 56, which contained 2 specimens with comb teeth oriented parallel to the sides of the limb, also contains several juveniles, presumably members of the same species as the adults. One of these (USNM 125441), a juvenile male at the N-1 stage of develop­ment, was dissected. Unlike the adults in the sample, the comb teeth of its seventh limbs are oriented pendicular to the sides of the limbs. Because of differences in orientation of the comb teeth have interpreted herein as being the result of individual variability." (Kornicker 1971, p. 194-196)

Scleroconcha gallardoi Kornicker

Scleroconcha gallardoi Kornicker, 1971:194, fig. 18.

HOLOTYPE.—USNM 125397, gravid ♀.

TYPE-LOCALITY.—Off Greenwich Island, 62°29.1′S, 59°41.0′W, 39 m, sandy mud bottom.

MATERIAL.—USNM 125838, 2 adult ♀ ♀ + 9 juveniles; USNM 125853, 1 gravid ♀; USNM 125960, 1 juvenile ♀, length 3.67 mm, height 2.16 mm; USNM 127259, 1 juvenile ♀, length 3.25 mm, height 1.95 mm; USNM 127260, 6 juveniles; USNM 127286, 1 N–1 ♀, length 3.59 mm, height 2.27 mm; USNM 127287, 1 N–1 ♀, length 3.52 mm, height 2.10 mm; USNM 127288, 3 juveniles; USNM 127470, gravid ♀; USNM 127471, 2 gravid ♀ ♀ + 1 adult ♀ + 28 juveniles; USNM 127500, 1 juvenile, length 3.22 mm, height 1.97 mm; USNM 138018, 1 specimen, length 3.77 mm, height 2.76 mm, + 2 juveniles (none dissected); USNM 138161, 1 gravid ♀.

USNM 125838 from Eastwind station 004 A; USNM 125853 from Deep Freeze II, USS Glacier, station 19; USNM 125860 from Deep Freeze III, Atka, station 28; USNM 127259, 127260 from IWSOE, USCGC Glacier, station 0009; USNM 127286–127288 from Eltanin Cruise 6, station 412; USNM 127470, 127471 from Hero Cruise 691, station 7; USNM 127500 from Deep Freeze I, Edisto, stations 5, 6, 8, combined; USNM 138018 from Hero Cruise 70–2, station 448; USNM 136161, from Yelcho station 70–39.

In addition, the following specimens collected by the Chilean Antarctic Expeditions were identified and returned to the Instituto Central de Biología, Concepción, Chile: XXIV Yelcho station 70–39, 2 gravid ♀ ♀, 2 adult ♀ ♀, 4 juveniles; XXIII Hero station 69–04, 1 N–1 ♂, length 2.98 mm, height 2.03 mm, 4 juveniles; XXIV, Yelcho station 70–30, 1 juvenile; XXIV, Yelcho station 7–35; XXIII, Hero station 69–2 (2), 1 juvenile ♀, length 3.52 mm, height 2.40 mm; XXIII, Hero station 69–46, 1 juvenile; XXII, Yelcho station 57, 1 adult ♀ without eggs, length 3.76 mm, height 2.85 mm.

DIAGNOSIS OF FEMALE.—Carapace similar in shape and ornamentation to S. appelloefi, carapace length 3.76 to 4.35 mm.

Seventh limb: Each limb with 10 bristles, 4 proximal, 6 distal; terminal comb consisting of 9 to 17 teeth with smooth margins; 1 peg (rarely 2) with smooth margin present opposite comb near middle of tip of limb.

Furca: Each lamella with 16 claws.

SUPPLEMENTARY DESCRIPTION OF ADULT FEMALE (Figures 197, 198a, 199–204).—Carapace size (Figure 189): USNM 125838, length 4.11 mm, height 2.69 mm; USNM 125853, length 4.35 mm, height 3.02 mm; USNM 127470, length 3.94 mm, height 2.80 mm; USNM 138161, length 4.04 mm, height 2.60 mm; specimen from Yelcho station 57, length 3.76 mm, height 2.85 mm.

Seventh limb: See Figures 204d-f.

Upper lip and anterior process: See Figures 203, 204a,b.

Rod-shaped organ: See Figure 204d.

Eggs: USNM 125853, 29 eggs; USNM 127470, 32 eggs; USNM 138161, 30 eggs.

Parasites: USNM 127286 (N–1 female) with 1 female choniostomatid and 9 ovisacs; USNM 127287 (N–1 female) with 1 choniostomatid female and 2 copepodites. USNM 125399 and other specimens with filaments (Figure 200a,b).

SUPPLEMENTARY DESCRIPTION OF N–1 MALE (USNM 125441, paratype) (Figure 198b,c).—Dimensions of carapace given by Kornicker (1971:196).

Second antenna (Figure 198b): Endopodite: 1st joint with 5 short bristles; 2nd joint elongate with 1 long proximal bristle with wreaths of long marginal spines, and 10–12 short distal ventral bristles with short marginal spines; 3rd joint with 1 long bare dorsal bristle and 2 short terminal bristles (Kornicker, 1971:196, incorrectly reported fewer bristles on the 1st and 2nd joints).

Lateral eye: Well developed with about 12 scattered ommatidia (Figure 198c).

DISTRIBUTION.—This species has been collected only in the Continental subregion of the Antarctic at depths of 33 to 1180 m (Figure 190).

BENTHIC