Harbansus bradmyersi Kornicker 1978

Harbansus bradmyersi

ETYMOLOGY.—The species is named for Mr. Brad L. Myers, Southern California Costal Water Research Project, E1 Segundo, California, who collected the specimens.

HOLOTYPE.—USNM 151989, 1 adult female, on slides and in alcohol.

TYPE-LOCALITY.—C-2 on continental shelf off Oxnard, California, depth 18.3 m.

PARATYPES (all from California).—USNM 156688, 1 ovigerous female from sta OC-3; USNM 156689, 1 ovigerous female from sta A-2; USNM 156690, 1 adult female from sta C-3; USNM 156691, 1 adult female from sta C-2; USNM 156692, 1 ovigerous female from sta K-1; USNM 156693, 1 adult female from sta OC-3. Specimens returned to Mr. Myers: 2 ovigerous females from sta OC-3a; 1 ovigerous female from sta C-2c; 5 ovigerous females, 1 adult female without eggs, 1 juvenile or adult female without eggs, from sta OC-3b; 1 female without eggs from off Santa Catalina Island.

DISTRIBUTION.—Off Oxnard, Laguna Beach, and Santa Catalina Island, California. Known depth range 10.7–27.4 m.

DESCRIPTION OF FEMALE (Figures 12–14; Plates 3–6).—Carapace: Elongate with long narrow rostrum and small projecting caudal process (Figure 12); dorsal margin more convex than ventral margin; sides parallel in dorsal view.

Ornamentation: Each valve with 3 faint horizontal ribs (Plate 3a–c); upper rib dorsal to central adductor muscle scars and extending onto rostrum, but not projecting past rostrum; middle rib ventral to central adductor muscle scars; lower rib just within ventral margin and not visible on all specimens; carapace with large shallow fossae (Plates 3a–d, 4a, 5a,b); surface with scattered long bristles mostly along anterior, anterodorsal, and ventral margins (Plates 3d–f, 4a–d, 5b–e), some bristles bifurcate (Plates 3e, 4c, 5d,e); 2 bristles present at inner end of incisur; bottom of fossae with crescents or wrinkles (Plates 3d, 4a, 5a,b); pustules visible on surface at high magnification (Plate 4).

Infold: Infold of rostrum with 6 or 7 long bristles (Figure 14c; Plates 5f, 6a,b); anteroventral infold with short bristle below inner end of incisur and with about 4 ridges parallel to valve margin; 2 to 4 small bristles present on anteroventral infold posterior to ridges; posteroventral infold with 6 short bristles near inner margin; ridge on infold of caudal process with 6 or 7 frondlike bristles (Figure 14d; Plate 6c–f); 1 short bristle present on posterior infold dorsal to caudal process (Plate 6c).

Selvage: Fringed lamellar prolongation present along anterior and ventral margins (Plates 3e, 6a); fringe may not be present on lamellar prolongation along posterior margin dorsal to caudal process.

Size: USNM 151989, length 0.95 mm, height 0.54 mm; USNM 156688, length 0.93 mm, height 0.53 mm; USNM 156689, length 0.92 mm, height 0.56 mm; USNM 156690, length 0.94 mm, height 0.55 mm; 156691, length 0.91 mm, height 0.58 mm.

First Antenna (Figure 13a): 1st joint: spines on medial surface and on ventral margin. 2nd joint: 1 dorsal bristle and spines along ventral and dorsal margins. 3rd joint: 3 bristles (1 ventral, 2 dorsal) and with few spines on medial surface and along ventral margin. 4th joint: 3 bristles (2 ventral, 1 dorsal). 5th joint: sensory bristle with 2 short proximal filaments, 1 short distal filament, and 3 long terminal filaments, including stem. 6th joint: medial bristle about three-fourths to four-fifths length of 5th joint. 7th joint: a-bristle about 3 times length of bristle of 6th joint, with short marginal spines; b-bristle about one-third longer than a-bristle, with 1 short distal filament and bifurcate tip; c-bristle with 1 short proximal filament, 2 short distal filaments, and 3 long terminal filaments, including stem. 8th joint: d- and e-bristles bare, same length as c-bristle; f-bristle same length as c-bristle, with 2 short proximal filaments, 1 short distal filament, and 3 longer terminal filaments, including stem; g-bristle about same length as f-bristle, with I short filament near middle. I short distal filament, and 3 longer terminal filaments, including stem. (Not all short filaments on sensory bristle and bristles of 7th and 8th joints shown in Figure 13a).

Second Antenna: Protopodite bare. Endopodite 2-jointed (Figure 13b): 1st joint short with 2 short bristles; 2nd joint elongate with 1 long ventral bristle near middle and 1 short terminal bristle. Exopodite: distal margin of 1st joint with minute medial bristle; bristle of joints 2–8 short, with stout ventral spines, no natatory hairs; 9th joint with 2 bristles (Figures 13c), ventral of these about same length as joints 2–9, with spines along ventral margin, also few along dorsal margin, dorsal bristle of 9th joint about same length as joints 5–9, with slender spines along dorsal margin, also few slender spines along ventral margin; joints 2–8 with spines forming terminal row; minute basal spines on some joints.

Mandible (Figures 13d, 14e): Coxale endite bifurcate, basal bristle not seen. Basale: spinous medial side with 2 short proximal bristles near middle; ventral margin with 1 long spinous distal bristle; lateral side with 2 bristles near ventral margin; dorsal margin with 1 bristle distal to middle and 2 terminals. Exopodite hirsute, reaching past middle of dorsal margin of 1st endopodite joint, with 2 terminal bristles. Endopodite: 1st joint with short spines forming rows on medial surface, and 3 spinous terminal bristles (2 long, 1 short) on ventral margin; 2nd joint with ventral margin with 4 distal bristles forming 2 groups, each with 2 bristles, middle of dorsal margin with 5 bristles; 3rd joint with 3 bristles and 3 claws (2 long with ventral spines, and 1 short, dorsal); USNM 151989 with aberrant right mandible having 2 short ventral bristles on 1st endopodial joint, no ventral bristles on 2nd joint, and 2 claws and 4 bristles on 3rd joint (Figure 13d).

Maxilla (Figure 13e): Endites I and II each with 6 bristles (not all shown in Figure 13e); endite III with 1 proximal and 6 terminal bristles. Coxale with spinous dorsal bristle. Basale with 3 long bristles (1 lateral, 1 medial, 1 ventral). Exopodite with 3 bristles (2 long, 1 short: inner long bristle with 4 or 5 very long spines proximal to middle; outer long bristle with short, faint, marginal spines; short bristle bare). Endopodite (twisted in Figure 13e): 1st joint with 1 α-bristle with long proximal spines and 2 β-bristles (lateral of these with swelling at base); end joint with 9 bristles including 3 claws (2 long stout, 1 short, ventral).

Fifth Limb (Figures 13f, 14f): Epipodial appendage with about 41 bristles. Endite I with 2 bristles; endite II with 4 bristles; endite III with about 8 bristles (not all endite bristles shown in Figure 13f). Exopodite: 1st joint with main tooth with well defined distal tooth having 2 main prongs and 2 smaller prongs, a 2nd large poorly defined tooth near inner edge of distal tooth; anterior distal margin of 1st joint with 1 bristle; 2nd joint with posterior side with stout proximal bristle with marginal spines and usual 3 bristles forming group (middle of these longer and stouter than others and weakly pectinate), large squarish tooth of 2nd joint with 2 nodes along inner margin; 3rd joint with 2 short spinous bristles on outer lobe and 3 bristles on inner lobe; 4th and 5th joints fused, with total of 5 bristles.

Sixth Limb (Figure 13g): One short bristle in place of epipodial appendage; endite I with 2 or 3 bristles; endite II with 3 terminal bristles; endite III with 5 terminal bristles; endite IV with 4 or 5 terminal bristles; end joint not projecting posteriorly, with 8 marginal bristles; posterior 2 bristles of end joint hirsute, remaining bristles and bristles of endites with long proximal and short distal spines; medial surface of limb hirsute.

Seventh Limb (Figure 14a): 2 bristles in proximal group (1 on each side); 4 bristles in distal group; each bristle with up to 4 bells and distal marginal spines; terminal comb with 6 recurved teeth; 3 spinous pegs present opposite comb.

Furca (Figure 13h): Each lamella with 6 claws; claws 1, 2, and 4 stout; claws 3, 5, and 6 short, slender; stout claws with teeth forming lateral and medial row along concave margin; distal medial teeth on claw larger than other teeth on claw; short slender claws with spines along anterior and posterior margins; hairs on lamella following claws and at bases of some claws.

Rod-shaped Organ (Figure 14b): Elongate with 6 or 7 faint sutures in proximal half; distal half with faint pustules on surface (faintly visible under oil immersion); tip rounded.

Eyes: Medial eye pigmented, bare (Figure 14b); lateral eyes small, faint, with 5 or 6 minute ommatidia, but eyes not visible on all specimens examined.

Y-Sclerite (Figure 13h): Typical for family.

Genitalia (Figure 13h): Sclerotized oval on each side proximal and anterior to furca.

Eggs: USNM 156688, 156689, 156692, each with 3 eggs.

Gut Content: USNM 151989 with unrecognizable organic particles and many grains of sediment. Species apparently detritus feeder.

Parasites: USNM 151989 and 156691 with 1 female choniostomatid copepod and 2 choniostomatid egg clones.

COMPARISONS.—The new species H. bradmyersi is closely related to H. paucichelatus (Kornicker, 1958). The tip of the 2nd joint of the endopodite of the female 2nd antenna of H. paucichelatus is either bare or has a minute spine, whereas that of H. bradmyersi bears a short bristle. Also, some bristles of the exopodite of the 2nd antenna of the adult female H. paucichelatus are long and bear natatory hairs, whereas, all the bristles on that limb of H. bradmyersi are short and are without natatory hairs. This indicates that adult females of H. paucichelatus are capable of swimming, whereas adult females of H. bradmyersi are restricted to burrowing. The caudal furca of H. paucichelatus usually bears 5 claws compared to 6 on the furca of H. bradmyersi.