Parasterope pollex Kornicker ex Bowman & Kornicker 1967

Parasterope pollex Kornicker, 1967

Cylindroleberis marinae.—Cushman, 1906:366, pl. 29.—Wass, 1965:28.—Wass and Andrews, 1979:212, 275. [Not Baird, 1850:257.]

Parasterope pollex Kornicker, in Bowman and Kornicker, 1967:9, figs. 4–7, pl. la, b.—Hulings, 1969:412.—Sohn, 1974:725, fig. Ig–i.—Bradford, 1975:3, 11, fig. la–c.—Siddiqui and Grigg, 1975:374.—Watling, 1975:281–284, 290, 292, 293, 304, 305.—Parker, 1975:107, 132, 140, 147, 170, 173, 175.—Stiles and Blake, 1976:230.—Baker, 1977:250.—Sheridan and Livingston, 1983:413.

Parasterope polex.—Hiruta, 1980:42

Parasterope sp. indet.—Kornicker, 1977:792, 794, fig. 3.

HOLOTYPE.—USNM 114048, ovigerous female, on slides and in alcohol.

TYPE-LOCALITY.—Hadley Harbor, Massachusetts.

MATERIAL.—See “Station Data with Specimens Examined.”

DISTRIBUTION.—Petpeswick Inlet, Nova Scotia, Canada; Hadley Harbor and Great Harbor, Woods Hole, Martha's Vineyard, Massachusetts; Lake Montauk, Long Island Sound, New York; Rehobeth Bay, Delaware; mouth of York River, Virginia; Tampa Bay, Placida Harbor, Alligator Harbor Anclote Anchorage, Florida.

SUPPLEMENTARY DESCRIPTION OF ADULT FEMALE (Figure 11).—Ventral and dorsal margins slightly convex, subparallel to each other, greatest height around middle (Figure 11a); anterior and dorsal margins evenly rounded; incisur below midheight.

Infold: Behind rostrum with 2 or 3 bristles along list, 4 or 5 bristles between list and incisur, and about 25 bristles anterior and dorsal to list; about 11 bristles on broad anteroventral infold; about 11 bristles along ventral infold to point near lowermost hyaline flap-like bristle on posterior list; broad posterior list with about 30 flap-like bristles and about 20 small bristles; 8–15 bristles between broad posterior list and posterior margin of valve (Figure 11c,m).

Size: USNM 144007, length 1.45 mm, height 0.73 mm, height 50 percent of length; USNM 152316A, length 1.38 mm, height 0.68 mm, height 50 percent of length, USNM 152316B, length 1.43 mm, height 0.68 mm, height 48 percent of length. USNM 152315, 9 specimens: length 1.41 mm, height 0.68 mm, height 48 percent of length; length 1.38 mm, height 0.65 mm, height 47 percent of length; length 1.38 mm, height 0.69 mm, height 50 percent of length; length 1.43 mm, height 0.67 mm, height 47 percent of length; length 1.40 mm, height 0.71 mm, height 51 percent of length; length 1.37 mm, height 0.63 mm, height 46 percent of length; length 1.38 mm, height 0.70 mm, height 51 percent of length; length 1.43 mm, height 0.69 mm, height 48 percent of length; length 1.31 mm, height 0.64 mm, height 49 percent of length; USNM 156765, length 1.33 mm, height 0.64 mm, height 48 percent of length; USNM 157123, length 1.38 mm, height 0.69 mm, height 50 percent of length; USNM 156711, length 1.29 mm, height 0.62 mm, height 48 percent of length; 2 specimens from Tampa Bay returned to R. Virnstein, length 1.43 mm, height 0.68 mm, height 47 percent of length, length 1.50 mm, height 0.74 mm, height 50 percent of length; USNM 157612, length 1.34 mm, height 0.68 mm; USNM 157613, length 1.31 mm, height 0.69 mm; USNM 157611, length 1.30 mm, height 0.64 mm; USNM 156708, length 1.60 mm; height 0.77 mm; height 48 percent of length; USNM 156710, length 1.56 mm, height 0.74 mm, height 47 percent of length; USNM 143751, length 1.59 mm, height 0.84 mm, height 53 percent of length; USNM 152452, length 1.66 mm, height 0.84 mm, height 50 percent of length; USNM 152580, length 1.64 mm, height 0.81 mm, height 49 percent of length; specimen from Lake Montauk, Long Island, New York, length 1.49 mm, height 0.80 mm, height 54 percent of length.

First Antenna (Figure 11d): 1st joint with many long spines on medial surface and few clusters of short spines on lateral surface. 2nd joint with 1 spinous dorsal bristle and spines forming rows on lateral and medial surfaces. 3rd and 4th joints fused; combined joints shorter than wide. 3rd joint with 5 spinous dorsal bristles and 1 minute ventral bristle. 4th joint with 1 dorsal bristle with short marginal spines, and 2 slender ventral bristles, both with faint, short, marginal spines (lateral of the bristles reaching middle of 6th joint, other longer); dorsal margin of 4th joint concave. Sensory bristle of 5th joint with 6 terminal filaments. 6th joint with 1 long medial bristle with short marginal spines. 7th joint: a-bristle short, claw-like; b-bristle about twice length of a-bristle, with 2 proximal and 2 distal filaments excluding stem; c-bristle longer than b-bristle, with 6 filaments including stem. 8th joint: d-bristle absent or represented by minute spine; e-bristle bare, slightly shorter than b-bristle; bristle; f-bristle about same length as b-bristle, forming angle with limb, with 3 short spinous filaments near middle and bifurcate tip; margin of f-bristle spinous distal to filaments near middle; g-bristle with 4 marginal filaments and bifurcate tip.

Second Antenna (Figure 11e,f): Protopodite with few hairs along dorsal margin, but without medial bristle. Endopodite distinctly 3-jointed with bare terminal bristle about 1 times length of stem. Exopodite: 1st joint bare; joints 3–8 with short spines forming row along distal margin and basal spines; basal spine on 8th joint about same length as 9th joint; 9th joint with lateral spine about same length as spine of 8th joint; bristle of 2nd joint reaching past 9th joint, with proximal stout spines along ventral margin and longer slender spines distally along both ventral and dorsal margins; bristles of joints 3–8 with proximal spines along ventral margin and natatory hairs distally along both margins; 9th joint with 3 bristles (1 short with short marginal spines, 1 medium and 1 long, both with natatory hairs); short bristle of 9th joint dorsal to others.

Mandible (Figure 11g): Coxale endite broke off specimen examined. Basale: endite with 4 pectinate terminal bristles, 1 dwarf bristle and glandular peg, and 3 triaenid bristles, each with 4 pairs of marginal spines excluding terminal pair; ventral margin near endite with 1 triaenid bristle with 3–4 marginal spines excluding terminal pair; dorsal margin with 2 slender bristles with short marginal spines; lateral and medial surfaces without spines. Exopodite about 65 percent of length of dorsal margin of 1st endopodite joint, hirsute, with 2 short bristles at tip. Endopodite: 1st joint with 3 long ventral bristles (1 of these missing on left limb of USNM 144007); dorsal margin of 2nd joint with stout spinous a-, b-, c-, and d-bristles, and 1 short proximal bristle with short marginal spines; ventral margin with 3 spinous terminal bristles; medial surface with few minute spines forming rows, 1 short cleaning bristle just distal to base of b-bristle, 4 cleaning bristles forming row just proximal to base of c-bristle, and 1 long, slender, spinous bristle medial and just proximal to base of d-bristle; lateral surface with medium slender bristle between b- and c-bristles and 1 long stout bristle between c- and d-bristles (the latter bristle missing on left limb of USNM 144007, but hole present indicating that it had been torn out); lateral bristle between b- and c-bristles shorter than c-bristle; lateral bristle between c- and d-bristles longer than c-bristle; end joint with stout dorsal claw, 4 long, stout, spinous bristles, and 1 short spinous bristle (the latter on medial side near middle of terminal margin).

Maxilla (Figure 11h): Epipodite pointed and hirsute, reaching to middle of dorsal margin of basale; endite I with 1 short and 3 long bristles; endite II with 3 long bristles. Basale: dorsal margin with 2 short bristles (1 proximal, 1 distal), both with bases on medial side of basale; lateral side with 1 short proximal bristle; medial side hirsute; ventral margin with 1 minute bristle near middle and 1 long, spinous, terminal bristle. Endopodite: 1st joint with short anterior bristle and medium length slender beta-bristle; end joint with 1 spinous bristle, longer and stouter than beta-bristle.

Fifth Limb (Figure 11i): Epipodial appendage with 52 bristles. Exopodial bristle of comb spinous, extending past end of comb; 1 short slender bristle ventral to base of comb; 2 pairs of short bristles present near ventral margin of comb.

Sixth Limb (Figure 11j): 1 minute medial bristle present in anterior proximal corner; anterior margin with 1 upper and 1 lower bristle; anterior corner of ventral margin with 2 plumose bristles; lateral sole without bristles; posteroventral margin with 11–13 bristles with long marginal hairs; limb hirsute.

Seventh Limb: Each limb with 12 bristles (6 proximal, 6 distal), each with 2–4 bells; terminus with opposing combs, each with 9–10 pinnate teeth.

Furca: Each lamella with 6 curved claws followed by 3 spinous bristles; main claws with slender hairs along distal half of convex margin; ventral margins with teeth forming lateral and medial row; about 10 minute teeth between longer teeth.

Bellonci Organ (Figure 11k): Elongate with rounded tip.

Eyes: Medial eye pigmented, with dorsal hairs (Figure 11k); lateral eye about diameter of medial eye, with about 5 ommatidia (Figure 11l).

Lips (Figure 11b): Upper lip hirsute, consisting of 2 lobes, each with large anterior spine; saddle between lobes with minute anterior spine; lateral flap on each side of mouth hirsute.

Dorsum (Figure 11n): Dorsal process finger-like, hirsute.

Genitalia: Consisting of oval sclerotized ring.

Eggs: USNM 144007 with 13 eggs in marsupium (Figure 11a); USNM 152316A, 8 eggs; USNM 152315A, 4 eggs; USNM 15671, 8 eggs; Tampa Bay specimen returned to R. Virnstein with 2 eggs; USNM 157612, 4 eggs; USNM 157613, 3 eggs; USNM 157611, 11 eggs; USNM 152850, 7 eggs; USNM 156710, 6 eggs; USNM 156709, 15 eggs; Lake Montauk specimen, 10 eggs.

SUPPLEMENTARY DESCRIPTION OF ADULT MALE (Figure 12).—Carapace with flat posterodorsal corner; dorsal margin linear or slightly concave, not convex as on female; posterior of each valve with vertical row of long hairs (Figure 12a). Infold not examined.

Size: USNM 144008, length 1.24 mm, height 0.62 mm, height 50 percent length. USNM 152315, 5 specimens: length 1.25 mm, height 0.65 mm, height 52 percent length; length 1.30 mm, height 0.66 mm, height 51 percent length; length 1.26 mm, height 0.67 mm, height 53 percent length; length 1.26 mm, height 0.64 mm, height 51 percent length; length 1.27 mm, height 0.66 mm, height 52 percent length. Average length (6 specimens) 1.26 mm, average height 0.65 mm, average height as percent of length 51; USNM 156712, length 1.37 mm, height 0.78 mm, height 57 percent of length; USNM 156708, length 1.51 mm, height 0.76 mm, height 53 percent of length.

First Antenna (Figure 12b,c): 1st and 2nd joints similar to those of female, except spines not observed on lateral surfaces. 3rd and 4th joints separated by distinct suture; combined joints longer than wide; 3rd joint with 6 spinous dorsal bristles and 1 minute ventral bristle; 4th joint with 1 spinous dorsal bristle and 2 slender, short, ventral bristles. Stout sensory bristle of short 5th joint with 6 terminal filaments and numerous marginal filaments. Dorsal margin of 6th joint slightly undulate (undulations larger on right limb), with spinous medial bristle reaching past distal end of a-bristle of 7th joint. 7th joint: terminal margin with 12 short spines forming medial row near middle; a-bristle short claw-like with faint teeth along ventral convex margin; b-bristle about 3-times length of a-bristle, with 5 filaments including stem; c-bristle very long and stout, with 20 short marginal filaments. 8th joint: d-bristle absent; e-bristle bare, shorter than b-bristle; f-bristle very long and stout, tip broken off, 18 short marginal filaments on remaining part; g-bristle longer than b-bristle, with 9 short filaments including stem (all filaments not shown).

Second Antenna: Exopodite: 1st joint with long hairs forming 3 clusters on lateral side of terminal margin; 2nd joint with short hairs forming 2 short rows on lateral side near middle of ventral margin, longer hairs along distal margin, and minute spines forming lateral row near base of natatory bristle; terminal margin of joints 3–8 with long hairs forming row, and on lateral side about 6 minute spines forming row near base of natatory bristle. Endopodite (Figure 12d): 3-jointed, with 3 small distal bristles on 2nd joint and 1 long proximal bristle on 3rd joint; 3rd joint reflexed on 2nd.

Mandible: Coxale endite broken off specimen examined. Basale endite similar to that of female except with only 1 or 2 triaenid bristles with 3–4 pairs of marginal spines excluding terminal pair; basale, exopodite, and 1st endopodial joints similar to those on female; 2nd endopodial joint with 2 proximal bristles on dorsal margin, 2 short cleaning bristles just distal to base of b-bristle, and long hairs and spines forming short rows on medial surface, otherwise similar to that of female; end joint similar to that of female.

Bellonci Organ (Figure 12e): Elongate with rounded tip.

Eyes: Lateral eye with about 17 ommatidia (Figure 12d). Medial eye about the same size as lateral eye, bare (Figure 12e).

Upper Lip (Figure 12f): Hirsute with anterior spine.

SUPPLEMENTARY DESCRIPTION OF UNDEVELOPED Male.—Kornicker (in Bowman and Kornicker, 1967:16) described 3 males that had numerous filaments on the sensory bristle of the 1st antenna, but on which the endopodite of the 2nd antenna was equivalent to the A-1 male instar. One of the specimens assigned USNM 152447 was similarly developed. Size: length 1.63 mm, height 0.84 mm.

SUPPLEMENTARY DESCRIPTION OF A-1 MALE (Figure 13).—Carapace similar in shape to that of adult female (Figure 13a).

Size: USNM 152318, length 1.10 mm, height 0.56 mm.

First Antenna (Figure 13b): 1st and 2nd joints similar to those of adult female except very few lateral spines observed on 2nd joint, 3rd and 4th joints fused on medial side, but separated by suture on lateral side; combined joints shorter than wide; 3rd joint with 6 spinous dorsal bristles and 1 minute ventral bristle; distal margin of 4th joint only slightly concave, otherwise similar to that of adult female. Sensory bristle of 5th joint with 1 short proximal and 6 long distal filaments. 7th joint similar to that of adult female except c-bristle with 11 filaments including stem. 8th joint similar to that of adult female except f-bristle with 12 filaments including tip.

Second Antenna (Figure 13c): Protopodite with short spines forming rows on medial side near dorsal margin. Exopodite similar to that of female except lateral spine of 8th joint consisting of 2 prongs, each about half length of 9th joint.

Mandible: Coxale endite with both terminal and distal dorsal bristles broken off on specimen examined; tip of ventral branch with 3–4 fine spines. Basale endite with 1 triaenid bristle with 3–4 pairs of marginal spines excluding terminal pair, endite otherwise similar to that of adult female. Basale: triaenid bristle with only 2 pairs of marginal spines excluding terminal pair, otherwise similar to that of adult female. Exopodite and endopodite similar to those of adult female, except no medial spines observed on 2nd endopodial joint.

Maxilla, Comb of Fifth Limb, Seventh Limb, Bellonci Organ (Figure 13e), Upper Lip (Figure 13f), Dorsum (Figure 13g): Similar to those of female.

Sixth Limb: Similar to that of adult female except with only 9 or 10 posteroventral bristles.

Furca: Each lamella with 6 claws followed by 2 bristles.

Eyes: Lateral eye smaller than eye of adult male but with about same number of ommatidia (Figure 13e). Medial eye with few hairs (Figure 13e).

Copulatory Organ: Present but poorly developed.

ONTOGENY AND SEXUAL DIMORPHISM.—The number of bristles on the dorsal margin of the 3rd joint of the 1st antenna is 6 for the A-1 male and adult male, but only 5 on the adult female. The sensory bristle of the 5th joint of the 1st antenna of the A-1 male bears a short proximal filament. This is absent on the adult female and probably also on the A-1 female, but the latter has not been examined. C-bristle of 7th joint and f-bristle of 1st antenna of A-1 male with more filaments than on adult female but less than on adult male. Exopodial joints of 2nd antenna with long hairs on adult male but not on A-1 male and adult female. Endopodite of 2nd antennae with usual dimorphism. Adult male with 2 proximal bristles on dorsal margin of 2nd endopodial joint of mandible; A-1 male and adult female with only 1 bristle in this location.

GEOGRAPHIC VARIABILITY IN CARAPACE SIZE.—Carapaces of specimens from the Gulf of Mexico are generally shorter and narrower than those from the west Atlantic (Figures 14, 15). Also, adult males from the Gulf of Mexico are smaller than adult females from that area; whereas, adult males and females from the western Atlantic are roughly the same size (Figure 14). Initially this was thought to indicate that 2 subspecies live in the study area. Then, both large and small forms were collected in Tampa Bay suggesting that they are not subspecies. I have found it expedient to refer both the large and small forms to P. pollex. The appendages of the western Atlantic form and those of the Gulf of Mexico form are quite similar (the supplementary description of appendages presented herein is based on specimens from the Gulf of Mexico).