Skogsbergia strophinx Kornicker 1991

Skogsbergia strophinx

Skogsbergia sp. Kornicker, 1987b:217.

ETYMOLOGY.—From the Greek strophinx (axle, pivot).

HOLOTYPE.—USNM 158307, adult male on slide and in alcohol.

TYPE LOCALITY.—Enewetak lagoon (holotype from sta B, plankton trap 7, night, coral rubble substrate).

PARATYPES.—Enewetak lagoon: Midwater trawl off Bokandretok Island: USNM 193626, 1 adult female on slide and in alcohol. Sta B, plankton trap 7, night, coral rubble substrate: USNM 193660, 6 specimens. Sta B, plankton trap 10, night, coral rubble substrate: USNM 193654, 1 adult female in alcohol. Sta B, plankton trap 10, night, coral reef substrate: USNM 193653, 3 adult females in alcohol.

DISTRIBUTION.—Enewetak Atoll.

DESCRIPTION OF ADULT MALE (Figures 5, 6a–f).—Carapace with convex ventral and dorsal margins, broad rostrum, shallow incisur, and projecting caudal process delimited from posterior margin by slight angle (Figure 5a).

Structures on Infold: Narrow list with anterior end ventral to incisur, continuing close to ventral margin of valve, and broadening to form stout bar (with minute indistinct pustules along posterior edge) near anterior edge of caudal process (Figure 5c).

Bristles of Infold: Infold of rostrum with 7 or 8 bristles forming vertical row and 2 or 3 bristles forming horizontal row near incisur (on holotype these bristles with bases connected by undulating line) (Figure 5b); 2 additional rostral bristles near infold midwidth; a pair of bristles (longer bifurcate) and 1 small bristle present at inner end of incisur; 1 short bristle at infold midwidth ventral to incisur (Figure 5b). Anteroventral infold and anterior third of ventral infold with 28 bristles (mostly divided and spinous); posterior half of ventral infold with 5 single bristles (these could be pore canals). Left valve only with single bristle near ventral end of broad bar of caudal process (Figure 5c). Broad bar of caudal process with transverse pore canals but no bristles; outer edge of infold of caudal process with about 11 minute pores (not shown).

Selvage: Lamellar prolongation with smooth outer edge present along anterior and ventral margins, terminating posteriorly near ventral end of caudal process; prolongation widest as well as narrowly striated in vicinity of incisur and divides at inner end of incisur (Figure 5b).

Carapace Size: USNM 158307, length 1.37 mm, height 0.81 mm.

First Antenna (Figure 5d): 1st and 2nd joints bare. 3rd joint with 2 small bristles (1 ventral, 1 dorsal); 4th joint elongate, with 2 small bristles (1 ventral, 1 dorsal); 5th joint short, triangular having sensory bristle with 8 or 9 long proximal filaments, 3 short distal filaments with marginal spines, and 1 very short bare filament near tip. 6th joint short, with long medial bristle (with few widely separated marginal spines) near dorsal margin (length of bristle equal to total length of joints 4–6 measured along dorsal margin). 7th joint a-bristle about ¾ length of bristle of 6th joint, with few widely separated marginal spines; b-bristle about 3 times length of a-bristle, same length as sensory bristle of 5th joint, with proximal node and sucker on short stout proximal filament and 4 distal filaments (2 filaments with 3 and 2 small suckers, respectively, next 2 filaments with marginal spines), stem distal to last filament with 6 marginal spines; c-bristle almost twice length of b-bristle, with proximal node and sucker on short proximal filament (diameter of sucker 1.6–1.7 times diameter of large sucker of b-bristle) and 9 distal filaments (2 filaments with 2 small suckers, followed by 6 filaments with marginal spines, and 1 small bare filament near tip). 8th joint: d- and e-bristles bare, about ¾ length of b-bristle; f- and g-bristles stout, about same length as c-bristle, with abundant long slender proximal filaments, followed by 8 stouter pectinate filaments and 1 small smooth subterminal filament (stem proximal to subterminal filament with spine).

Second Antenna (Figure 5e): Protopodite with short, bare, medial bristle. Endopodite 1-jointed (could be interpreted to have minute 2nd joint), with 4 proximal bristles (3 short and 1 about twice as long) and 1 long terminal filament (filament could be interpreted to be on minute 2nd joint). Exopodite: 1st joint with few indistinct spines along concave margin; bristle of 2nd joint reaching to about 8th joint, with proximal hairs (13 ventral, 11 dorsal) on unringed segment, 2 slender dorsal spines and 7 stout ventral spines on following ringed segments, and short terminal segment with closely spaced rings; bristles of joints 3 and 4 with natatory hairs and long slender spines (shorter than hairs) just proximal to bristle midlength; bristles of joints 5–8 with natatory hairs, no spines; 9th joint with 4 bristles (2 long, 1 medium, 1 short dorsal) with natatory hairs, no spines; joints 3–8 with basal spines increasing in length on distal joints; basal spine of 8th joint 3.6 times length of 9th joint; 9th joint with lateral spine about same length as joint; joints 2–8 with indistinct minute spines forming row along distal margins.

Mandible (Figure 5f): Coxale endite spinous with 2 stouter terminal spines with small peg between them; with small basal bristle (not shown). Basale: dorsal margin with 1 bristle near midlength and 2 subterminal; ventral margin with 3 short medial a-bristles, 1 short lateral b-bristle, 2 small ventral c-bristles with small peg proximal to them, and 1 long d-bristle with long spines. Exopodite spinous, about ¾ length of dorsal margin of 1st endopodial joint, with 2 bristles (base of proximal bristle near midlength of exopodite, distal bristle about 1/3 length proximal bristle). 1st endopodial joint with 4 ventral bristles. 2nd endopodial joint: medial surface with short spines forming rows (not shown); ventral margin with short spines, and 2 (weakly ringed) and 2 short slender pointed unringed bristles (paired bristles about same length and width); dorsal margin with 13 bristles (5 long bristles, 1 proximal, medium length bristle, 1 short ringed bristle (with long distal anterior spines) medial to 1st long bristle, 1 short ringed bristle medial to 3rd long bristle, and 5 short medial unringed bristles). 3rd endopodial joint with 3 claws (dorsal claw obscured, others with proximal ventral teeth) and 4 ringed bristles.

Maxilla (Figure 5g–i): Endite I with 11 bristles, endite II with 7 bristles, endite III with 1 proximal and 6 distal bristles (Figure 5g). Precoxale with dorsal fringe. Coxale with plumose dorsal bristle. Basale with 1 short dorsal terminal bristle and 2 ventral terminal bristles (1 short, 1 long with long spines). Exopodite hirsute, with 1 hirsute distal bristle and 2 terminal bristles (outer bristle hirsute). Endopodite: 1st joint with triangular cutting tooth, 2 slender bare ringed alpha-bristles, and 2 shorter ringed beta-bristles (inner with few marginal hairs, outer bare) (Figure 5h,i); 2nd joint with 4 bare ringed a-bristles, 3 pectinate claws plus about 5 addidonal obscured bristles (see description of adult female below).

Fifth Limb (Figure 6a): Epipodite with 50 plumose bristles. Endite I with 7 spinose bristles; endite II with about 6 bristles; endite III with about 7 bristles (not all endite bristles shown). Protopodite with elongate sclerotized process. Exopodite: 1st joint: main tooth with smooth peg, 6 cuspate teeth, and spinous bristle proximal to peg; anterior side with 3 bristles forming row and 1 proximal bristle near protopodial process (not shown). 2nd joint with 4 stout pectinate unringed a-bristles, 2 pectinate ringed b′-bristles, 4 pectinate ringed b″-bristles, 1 spinous ringed posterior c-bristle, and 1 spinous anterior d-bristle (not shown). 3rd joint: inner lobe with short spinous proximal bristle and 2 bare terminal bristles (outer bristle unringed); outer lobe hirsute, with 2 terminal bristles with few long hairs. 4th and 5th joints hirsute, fused, each with paired bristles; indistinct small peg between pairs.

Sixth Limb (Figure 6b): Epipodite with 4 short bristles. Endite I with 3 short, spinous, proximal, medial bristles and 1 or 2 terminal bristles; endite II with 2 short, spinous, proximal, medial bristles and 2 spinous terminal bristles (1 very small); endite III with 1 long, spinous, proximal, medial bristle and 4 terminal bristles (1 short); endite IV with 1 short, spinous, proximal, medial bristle and 6 terminal bristles (1 short). End joint with 10–13 short spinous bristles followed by 2 longer plumose bristles; lateral edge with stiff spines; medial surface hirsute.

Seventh Limb: Proximal group with 7 bristles (3 or 4 on each side), each with 3–6 bells; distal group with 12 or 13 bristles (6 or 7 on comb side, 6 on jaw side), each with 1–6 bells (Figure 6c). Comb with about 11 obscured teeth (Figure 6d). Jaw difficult to resolve, either bare or with few minute teeth at distal end.

Furca (Figure 6e): Each lamella with 8 claws; claw 2 nonarticulated, remaining claws articulated; claw 5 stouter and longer than claw 4; all claws with small uniform teeth along posterior margin (not shown); claw 1 with 8 distal medial teeth (most larger than teeth along posterior margin) (not shown); right lamella slightly anterior to left.

Bellonci Organ (Figure 5j): Cylindrical, short, with rounded tip.

Eyes: Lateral eye with 27–30 amber-colored ommatidia, without black pigment between ommatidia (Figure 5a). Medial eye slightly smaller than lateral eye, amber colored (Figure 5j).

Upper Lip (Figure 6f): With unpaired anterior part bearing fairly large glandular openings, and paired posterior part followed by small lateral lobe with 2 or 3 glandular openings.

Genitalia (Figure 6e): Lobate copulatory organ on each side of body.

Anterior of Body (Figure 6f): With rounded anterior process between medial eye and upper lip.

Posterior of Body: Evenly rounded, bare.

Y-Sclerite (Figure 6e): Typical for family.

DESCRIPTION OF ADULT FEMALE (Figure 6g–q).—Carapace with convex dorsal margin, slightly convex ventral margin, broadly rounded posterodorsal margin, and slightly projecting caudal process not delimited by angle from posterior margin of valve dorsal to caudal process (Figure 6g). Inferior corner of rostrum forming right angle in lateral view, and with incisur deeper than that of male carapace; tip of rostrum with minute protuberance (Figure 6h). Carapace surface smooth.

Structures on Infold: Similar to those of adult male.

Bristles of Infold: Infold of rostrum with 14 distal bristles, and 1 proximal bristle and 2 bristles near inner end of incisur (Figure 6h). 1 small bristle just ventral to inner end of incisur. Anteroventral infold and anterior third of ventral margin with 23 or 24 bristles along list and several small bristles inward from list (not all shown in Figure 6h); 2 bristles on ventral list at valve midlength; posterior half of ventral list with widely spaced minute bristles. Left valve with single bristle near ventral end of broad bar of caudal process.

Selvage: Similar to that of adult male.

Carapace Size: USNM 193626, length 1.64 mm, height 1.03 mm. USNM 193653, 3 specimens: length 1.62 mm, height 1.03 mm; length 1.59 mm, height 0.99 mm; length 1.62 mm, height 1.02 mm. USNM 193654, length 1.61 mm, height 1.04 mm.

First Antenna (Figure 6i,j): 1st joint bare. 2nd joint spinous. 3rd and 4th joints each with 2 bristles (1 ventral, 1 dorsal). Sensory bristle of 5th joint with 9 stout proximal filaments followed by 3 slender filaments and bifurcate tip. 6th joint with terminal bristle with length about twice width of 6th joint (bristle missing on left limb of USNM 193626 (Figure 6i), but present on right limb (Figure 6j)). 7th joint: a-bristle about ¾ length of bristle of 6th joint; b-bristle about 3 times length of a-bristle, with about 5 marginal filaments; c-bristle longer than sensory bristle of 5th joint, with marginal filaments. 8th joint d- and e-bristles long, bare, with blunt tips; f- and g-bristles long with marginal filaments.

Second Antenna: Protopodite with short medial bristle (Figure 6k). Endopodite 1-jointed, with 4 proximal bristles (2 long, 2 short) and 1 long terminal filament (Figure 6k). Exopodite not examined in detail but in general similar to that of adult male.

Mandible: Short bristle of exopodite reaching distal end of 1st endopodial joint. Dorsal claw of 3rd joint of endopodite bare, other 2 claws with proximal teeth. Limb otherwise similar to that of adult male.

Maxilla (Figure 6l): 2nd endopodial joint with 4 bare ringed a-bristles, 3 pectinate b-bristles (anterior ringed, others unringed), 2 pectinate ringed c-bristles, and 3 pectinate claw-like d-bristles (posterior ringed distally, others unringed). Limb otherwise similar to mat of adult male.

Fifth Limb (Figure 6m): Similar to those of adult male.

Sixth Limb: Epipodite with 4 short bristles. Endite I with 3 short, spinous, proximal, medial bristles and 1 spinous terminal bristle; endite II with 2 short, spinous, proximal, medial bristles and 2 spinous terminal bristles (1 very small); endite III with 1 long, spinous, proximal, medial bristle and 4 terminal bristles (1 short); endite IV with 1 long, spinous, proximal, medial bristle and 6 terminal bristles (1 short). End joint with 12 or 13 short spinous bristles followed by 2 longer plumose bristles; lateral edge with stiff spines; medial surface hirsute.

Seventh Limb: Proximal group with 7 bristles (3 or 4 on each side), each with 4–6 bells; distal group with 6 bristles on comb side, 5 on jaw side, each bristle with 1–6 bells. Comb with about 11 teeth. Jaw obscured.

Furca (Figure 6n), Bellonci Organ (Figure 6o), Upper Lip (Figure 6o), Anterior of Body (Figure 6o), Posterior of Body, and Y-Sclerite: Similar to those of adult male.

Eyes: Lateral eye with 27 amber-colored ommatidia, without black pigment between ommatidia (Figure 6p). Medial eye (Figure 6o) smaller than lateral eye, amber colored but lighter shade than ommatidia of lateral eye.

Genitalia (Figure 6q): Genital lobe with attached spermatopore on each side of body anterior to furca.

Gut Content: Gut of USNM 193626 with several compound eyes of larval decapods visible through gut wall.

COMPARISONS.—S. strophinx is close to S. curvata Poulsen, 1962, and S. menezi Kornicker, 1970, and they could be conspecific. Some morphological differences between adult males of the 3 species are listed in Table 3, but some of the differences could be the result of intraspecific variability, which is not known. The bristle of the 6th joint and also the a-bristle of the 7th joint of the 1st antenna of the male 5. strophinx are longer man those of S. curvata and S. menezi. The dorsal bristles of the 3rd and 4th joints of the 1st antenna of the male S. strophinx are much shorter than those of the male S.curvata. The 1st endopodial joint of the 2nd antenna of S. strophinx differs from that of S. curvata in having 4 rather than 5 proximal bristles. The tip of the anterior process between the upper lip and medial eye of the male is bifurcate on 5. menezi and rounded on S. strophinx.

Cypridinodes Brady, 1902

Cypridinodes Brady, 1902:187.

TYPE SPECIES.—Cypridinodes favus Brady, 1902:187, monotypy.

COMPOSITION.—Including a new species described herein, 12 species are referred to this genus: C. bairdii (Brady, 1866), C. wyvillethomsoni (Brady, 1880), C. favus Brady, 1902, C. asymmetrica (Müller, 1906), C. acuminata Skogsberg, 1920, C. dorsocurvata (Graf, 1931) [new combination], C. reticulata Poulsen, 1962, C. inermis, Poulsen, 1962, C. galatheae. Poulsen, 1962, C. minuta Poulsen, 1962, C. concentrica Kornicker, 1979, and C. plax, new species.

DISTRIBUTION.—Indo-West-Pacific region. The range of Cypridinodes extends eastward into the Pacific as far as the Samoa Islands in the South Pacific and Bikini Atoll in the North Pacific, and westward into the Indian Ocean to the vicinity of Madagascar and into the Red Sea. The northernmost extent of its range is the South China Sea (Pescadoro Islands); the southernmost extent of its range is in the Tasman Sea (latitude 43°35′S).

CORRECTION.—Kornicker (1970b:19) mistakenly listed Cypridina elongata instead of Cypridina bairdii as a synonym of Cypridinodes bairdii.