Polycopissa anax Kornicker & Iliffe 1989

Polycopissa anax

Polycope spp.—Maddocks and Iliffe, 1986:73 (part).

ETYMOLOGY.—From the Greek anax (lord, master, king).

HOLOTYPE.—USNM 193366, 1 adult male in vial (not illustrated).

TYPE LOCALITY.—Bermuda: Roadside Cave, 0–1.5 m, 27 Aug 1982.

MATERIAL.—Bee Pit Cave, 23 Jan 1984: USNM 193352, 1 adult male on slide. Christie's Cave, 24 Nov 1982: USNM 193364A, 1 instar V female in vial; USNM 193364B, 2 adult females in vial; USNM 193364C, 1 instar V female on slide. Fern Sink Cave, 24 Jul 1984: USNM 193365A, 1 adult female on slide; USNM 193365B, 1 adult male in vial; USNM 193365C, 2 adult females in vial. Roadside Cave, 27 Aug 1982: USNM 193361, 19 specimens in vial; USNM 193366, 1 adult male in vial (holotype); 12 Nov 1982: USNM 193351, 1 adult male on slide; USNM 193354, 1 adult male on slide; USNM 193355A.B, 2 instar I on slides; USNM 193356A.B, 2 instar III on slides; USNM 193357, 1 instar II on slide; USNM 193360A, 1 early instar on slide (length 0.18 mm, height 0.12 mm); USNM 193360B, 3 early instars in vial. Tucker's Town Cave, 8 Sep 1982: USNM 193362A, 1 instar V female on slide, USNM 193362B, 6 specimens in vial (2 adult males, 2 adult females, 1 instar I, 1 instar II); USNM 163362C, 1 adult male in vial; 16 Mar 1984: USNM 193363, 3 females and 2 males in vial. Walsingham Sink Cave, 13 Aug 1982: USNM 193353, 1 adult female on slide.

DISTRIBUTION (Figure 45).—Bermuda: Bee Pit Cave: 23 Jan 1984; Christie's Cave: 24 Nov 1982; Fern Sink Cave: 24 Jul 1984; Roadside Cave: 27 Aug 1982 (type locality), 12 Nov 1982; Tucker's Town Cave: 8 Sep 1982, 16 Mar 1984; Walsingham Sink Cave: 13 Aug 1982.

DIAGNOSIS.—Carapace with 7 or 8 small wedge-shaped central adductor muscle attachments forming oval. 1st antenna with 3 sutures forming 4 distinct segments without dorsal processes; penultimate joint of adult male with 2 spatulate bristles. Male endopodite of 2nd antenna: 1st joint with lateral elongate sclerotized process with recurved tip; 2nd joint with short sclerotized dorsal process. Mandible: basale with 3 ventral bristles; exopodite with 2 terminal bristles (posterior bristle indistinct). Maxilla with exopodite longer than basale. Furca: each lamella with 6 claws followed by slender bristle; 2 or 3 unpaired bristles following lamellae; a triangular process between adjacent claws; each claw with narrow transparent vellum along posterior edge. Bellonci organ comprising 2 short stout hirsute bristles.

DESCRIPTION OF ADULT MALE (Figures 46–48f).—Elongate, smoothly rounded, shell translucent, colorless; anteroventral margin slightly less rounded and with 2 minute triangular processes (Figures 46, 48a; processes not shown in Figure 46a).

Ornamentation: Surface smooth without visible ornamentation at low magnification but in anteroventral quarter of valves faint ridges and punctae visible in transmitted light with × 50 objective (Figure 48a). Anteroventral margin with 2 minute triangular processes (Figure 46d.f). About 7 long hairs present along anterodorsal margin, extremely sparse elsewhere (Figure 48a). Glands composed of closely packed globules, appearing slightly yellow in preserved valves when viewed with transmitted light, forming discrete patches between vestment and shell, and more abundant along margins than near valve middle (Figure 46b–d). External pores present just within valve margins (Figure 46b–d, 48a) leading to glands through tube having bulbous section near pore; similar pores sparsely distributed over external surface of valves (Figure 48a); the marginal pore just ventral to ventral of the 2 triangular processes on anteroventral margin of valves of USNM 193351 with extruded substance emanating from it (Figure 46a,d–f), extruded substance not present on valves of USNM 193351 (Figure 46a).

Infold (Figure 46b–f): Infold broader along anterior margin (Figure 46b,e); right valve with well-defined list extending from midheight of anterior margin to midheight of posterior margin (Figure 46c,d); list of left valve less extensive and defined (Figure 46f).

Selvage (Figure 46c,d): Broad lamellar prolongation along anterior, ventral, and posteroventral margins, with slender marginal hairs along anteroventral, ventral, and posteroventral margins, but longest along anteroventral margin (Figure 46d); margin of prolongation smooth dorsal to lower of the 2 anteroventral triangular processes (Figure 46d); edge of prolongation appearing slightly sclerotized between the 2 anteroventral triangular processes.

Vestment: Spines present on anterior, posterior, and dorsal areas (Figure 46c).

Central Adductor Muscle Attachments (Figures 46a, 47a): Comprising 7 or 8 wedge-shaped scars forming oval. Muscle consisting of 3 compact strands where passing through body and then subdividing into 7 or 8 strands just before shell.

Carapace Size: USNM 193351, 193354, length 0.25 mm, height 0.21 mm; USNM 193352, length 0.25 mm, height 0.20 mm; USNM 193366 (holotype), length 0.26 mm, height 0.20 mm; USNM 193362B, 2 specimens, length 0.25 mm, height 0.20 mm, length 0.26 mm, height 0.21 mm; USNM 193365B, 0.25 mm, height 0.21 mm.

First Antenna (Figures 41a–c, 48b): 1st joint with dorsal spines and well-defined distal suture. Joints 2–5 fused: inferred 2nd joint with short dorsal spines and terminal dorsal bristle on distinct projection; joints 3–5 with short dorsal spines, medial spines distal to midlength (3rd joint?) and short ventral bristle on inferred 5th joint. 6th joint elongate (62 percent length of joints 2–5), with well-defined proximal and distal sutures, 1 short dorsal bristle, and 4 medial bristles near ventral margin (2 middle bristles with spatulate tips (Figures 47b, 48b)). Joints 7 and 8 fused with 5 bristles (2 long, 1 medium, 2 short; long and medium bristles with indistinct rings proximally).

Second Antenna (Figure 47a,d,e): Protopodite triangular, with few hairs near midlength of dorsal margin. Exopodite with 9 joints: joints 1–8 with long bristle with natatory hairs; joint 9 with 3 bristles (1 medium, 2 short). Endopodite 3-jointed: 1st joint with terminal, lateral, club-like sclerotized process with recurved tip; 2nd joint with 1 indistinct short ventral bristle, a short sclerotized dorsal process, and 5 terminal bristles (3 long, 2 medium); 3rd joint with 4 terminal bristles (3 long, 1 medium).

Mandible (Figure 47a,f,g): Coxale endite well developed, tip obscure. Basale with 3 ventral bristles and 1 dorsal bristle at midlength. Exopodite broadening distally, with 2 terminal bristles (anterior bristle long with long marginal hairs; posterior bristle indistinct, about half length of anterior bristle, with extremely thin marginal hairs difficult to resolve with light microscope. Endopodite: 1st joint with 2 long distal dorsal bristles, and 3 shorter hirsute ventral bristles; end joint with 2 bristles.

Maxilla (Figure 47a,h,i): Precoxale endite with proximal ventral papillae, 4 or 5 slender bristles and 1 short, stout, claw-like bristle. Coxale with dorsal proximal hump forming attachment for internal muscle extending to basale just proximal to base of exopodite; with 2 endites (proximal endite with 3 bristles; distal endite with 5 bristles). Basale: proximal margin indicated by base of muscle attaching to proximal end of convex dorsal margin and extending into exopodite; distal margin indicated by slight indentations in dorsal margin at base of exopodite and ventral margin at base of endopodite; sutures separating basale from coxale and 1st endopodial joint clearly visible only on medial side; ventral margin with 2 bristles (1 very long). Endopodite: 1st and 2nd joint separated by well-defined suture; 1st joint with 1 distal ventral bristle; 2nd joint with 2 dorsal bristles (longer bristle with few long proximal hairs), and 3 long ventral bristles (marginal hairs not observed); end joint with 3 long stout bristles (dorsal of these with long proximal hairs). Exopodite slightly shorter than endopodite, with distal dorsal hairs and 8 terminal bristles.

Fifth Limb (Figure 47a,j): Epipodite with 11 bristles (proximal 3 bristles missing on illustrated limb). Coxale with 2 short, distal, medial bristles, and 1 short, terminal, anterior bristle. Basale with 2 distal posterior bristles, 1 distal anterior bristle, and hirsute anterior margin. Short exopodite with 6 terminal bristles. Endopodite with single small joint with 2 bristles (anterior bristle broad, short, hirsute; posterior bristle slender, about twice length of anterior bristle).

Furca (Figures 47a,k, 48e): Each lamella with anterior terminal process and 6 claws (with slender teeth and narrow velum along posterior margins) followed by 1 slender bare bristle; a triangular process present between adjacent claws (process between claws 5 and 6 very small). 2 or 3 slender, bare, unpaired, closely spaced bristles proximal to lamellae. Posterior edges of anterior terminal process and triangular processes between claws with well-defined S-shaped line extending proximally into lamellae (line extending from small process between claws 5 and 6 almost straight); medial surface of lamellae with short spines forming rows.

Bellonci Organ (Figures 47a, 48d): 2 stout hirsute bristles.

Posterior of Body (Figures 47a,k, 48e): With 3 well-defined segments; proximal segment with long spines forming row; distal segments with small spines.

Copulatory Organ (Figures 47k, 48e): On left side of furca, compact.

Epizoa: USNM 193365B with 2 funnel-shaped protistans on posterodorsal margin of left valve (Figure 48f) and 1 on right.

DESCRIPTION OF ADULT FEMALE (Figure 48g–k).—Carapace, ornamentation, and central adductor muscle attachments similar to those of adult male (Figure 48g).

Carapace Size: USNM 193353, length 0.26 mm, height 0.21 mm; USNM 193362B, 2 specimens, length 0.28 mm, height 0.22 mm; length 0.27 mm, height 0.23 mm; USNM 193363, 3 specimens, length 0.25 mm, height 0.22 mm, length 0.26 mm, height 0.22 mm, length 0.28 mm, height 0.23 mm; USNM 193365C, length 0.29 mm, height 0.25 mm.

First Antenna (Figure 48h,i): Joints 1–5 similar to those of adult male. 6th joint shorter than that of male (length 43 percent length of joints 2–5), with 1 short dorsal bristle and 2 medial bristles near ventral margin (inner bristle very small, no spatulate bristles). Bristles of joints 7 and 8 similar to those of adult male.

Second Antenna (Figure 48h,j): Protopodite and exopodite similar to those of adult male. Endopodite 3-jointed: 1st joint elongate with 1 short lateral bristle; 2nd joint broadening distally, with 1 slender dorsal bristle and 5 terminal ventral bristles (3 medial, 2 lateral (1 slender, 1stout)); small 3rd joint with 4 bristles.

Mandible: Similar to that of adult male.

Maxilla: Exopodite with 9 bristles. Limb otherwise similar to that of adult female.

Fifth Limb: Basale with 3 distal posterior bristles. Limb otherwise similar to that of adult male.

Bellonci Organ (Figure 48h), Furca and Posterior of Body (Figure 48k): Similar to that of adult male.

DESCRIPTION OF INSTAR I (Figure 49a–e).-Carapace similar in shape to that of adult, uncalcified.

Central Adductor Muscle Attachments: Indistinct but comprising about 5 wedge-shaped scars forming oval.

Carapace Size: USNM 193355A,B, 2 specimens, length 0.15 mm, height 0.12 mm; length 0.15 mm, height 0.90 mm; USNM 193362B, length 0.14 mm, height 0.12 mm.

First Antenna (Figure 49a,c): Similar to adult in having sutures between joints 1 and 2, 5 and 6, and 6 and 7; joints 2–5 and 7 and 8 fused. Joint 1 with dorsal spines; joint 2 with long dorsal bristle reaching 6th joint; joints 2–5 with dorsal spines and medial spines distal to midlength; joint 6 with 1 short ventral bristle; fused joints 7 and 8 with 3 bristles (2 long stout, 1 medium slender).

Second Antenna (Figure 49a,d): Protopodite similar to that of adult. Exopodite with 8 joints: joints 1–7 with long bristle with natatory hairs; 8th joint with 2 bristles (1 medium, 1 small). Endopodite 3-jointed: 1st joint bare; fused 2nd and 3rd joints with 1 short dorsal bristle (on 2nd joint) and 6 distal bristles.

Mandible and Maxilla (Figure 49a): Well developed.

Fifth Limb (Figure 49a,b): Developed, exopodite and endopodite with bristles, but epipodial bristles not observed (possibly not resolved).

Furca (Figure 49e): Each lamella with anterior terminal process and 2 claws; a triangular process between claws 1 and 2 and following claw 2. 2 slender unpaired bristles following lamellae; without S-shaped line extending proximally into lamella from posterior edges of anterior terminal process and triangular processes.

Bellonci Organ, Posterior of Body: Similar to those of adult.

DESCRIPTION OF INSTAR II (Figure 49f).—Carapace similar to that of adult male.

Carapace Size: USNM 193357, length 0.17 mm, height 0.15 mm; USNM 193362B, length 0.16 mm, height 0.14 mm.

First Antenna (Figure 49f): Similar to that of instar I.

Second Antenna (Figure 49f): Protopodite similar to that of instar I. Exopodite with 8 joints: joints 1–7 with stout natatory bristle; joint 8 with 2 bristles (1 short, 1 medium). Endopodite similar to that of instar I.

Maxilla (Figure 49f): Well developed.

Fifth Limb (Figure 49f): Well developed; epipodite with at least 5 bristles.

Furca (Figure 49f): Each lamella with anterior terminal process and 3 claws; a triangular process between claws 1 and 2, and following claw 3; none between claws 2 and 3; without S-shaped line extending proximally into lamella from posterior edges of anterior terminal process and triangular processes; without medial spines forming rows on lamellae; 2 unpaired bristles following lamellae.

Bellonci Organ and Posterior of Body (Figure 49f): Similar to those of instar I.

DESCRIPTION OF INSTAR III (Figure 49g–i).-Carapace similar to that of adult, uncalcified.

Carapace Size: USNM 193356A,B, length 0.17 mm, height 0.12 mm, length 0.20 mm, height 0.17 mm.

First Antenna (Figure 49g): Similar to that of instar I.

Second Antenna: Protopodite similar to that of instar I. Exopodite with 9 joints; joints 1–8 with 1 long bristle; 9th joint minute, with 2 bristles (1 medium, 1 short). Endopodite: 1st joint bare; 2nd and 3rd joints fused; with 1 short dorsal bristle (on 2nd joint) and 7 terminal bristles.

Mandible, Maxilla, Fifth Limb: Well developed.

Furca (Figure 49h): Each lamella with anterior terminal process and 4 claws; a triangular process between claws 1 and 2, and 2 and 3, and following claw 4; none between claws 3 and 4; without S-shaped line extending proximally into lamellae from posterior edges of anterior terminal process and triangular processes; without medial spines forming rows on lamellae; 2 unpaired bristles following lamellae.

Bellonci Organ (Figure 49i), Posterior of Body (Figure 49h): Similar to those of adult.

DESCRIPTION OF INSTAR V FEMALE (Figure 49j).-Carapace similar to that of adult.

Carapace Size: USNM 193362A, 1 specimen, length 0.23 mm, height 0.19 mm; USNM 193364C, 1 specimen, length 0.23 mm, height 0.19 mm; USNM 193364A, length 0.25 mm, height 0.20 mm.

First and Second Antennae: Similar to those of adult female.

Mandible, Maxilla, Fifth Limb: Not examined in detail but similar to those of adult female.

Furca (Figure 49j): Differs from that of adult male and female in not having a small process between claws 5 and 6, in having small process in place of bristle following claw 6, and in not having S-shaped line extending proximally into lamella from posterior edges of anterior terminal process and triangular process; lamellae without medial spines forming rows; 3 unpaired, closely spaced bristles following lamellae.

Bellonci Organ, Posterior of Body (Figure 49j): Similar to those of adult.

FOOD.—The guts of many specimens contain unidentifiable brown particles.

ONTOGENY AND SEXUAL DIMORPHISM.—It is estimated that the youngest instar in the collection is Instar I, because of having only 2 furcal claws (see “Recognition of the First Instar of Cladocopina,” p. 66, herein). An additonal furcal claw is added in Instar II (total 3), and another in instar III (total 4). Instar IV is absent from the collection but it is predicted to have 5 claws (Table 22). Instar V has 6 claws, the same number as the adult. Juveniles have a triangular process following the last claw; in the adult the process is replaced by a bristle. A very low triangular process between claws 5 and 6 of the adult furca is absent on Instar V (A-1 instar). An S-shaped well-defined line on the adult furca extending proximally into the lamellae from the posterior edges of the anterior terminal triangular process (present on all instars) and the triangular processes between claws is absent on juveniles. The species has a total of 6 instars of which 5 are juveniles. This is 1 less than the number of instars of Metapolycope duplex described herein.

Instar I has all five appendages; exopodial and endopodial bristles are present on the 5th limb (epipodial bristles were not seen on the epipodite, but these thin bristles are difficult to resolve even on later instars so they could be present).

The 1st antenna of the adult female has 2 medial bristles near the ventral margin of the 6th joint, whereas that of the adult male has 4 of which the middle 2 have spatulate tips (probably used for grasping female). Instars V (A-1) in the collection have 2 simple bristles on the 6th joint similar to those of the adult female, and because of this they were interpreted to be females. A-1 males of Metapolycope hartmanni (Kornicker and van Morkhoven, 1976, fig. 14a) and of M. duplex, herein, have modified medial bristles on the 6th joint of the 1st antenna.

The endopodite of the 2nd antenna of the adult male has a sclerotized club-like process with recurved tip on the 1st joint, and a short sclerotized dorsal process on the 2nd joint, both absent on the adult female. The adult male has a bulky copulatory organ proximally of the left lamella of the furca.

COMPARISONS.—Chavtur (1981a:57) recognized with certainty only 1 species in the genus Polycopissa: P. japonica Chavtur (1979:97), known only from the female. The carapace of P. japonica bears only 3 central adductor muscle attachments compared to 7 or 8 on P. anax. On the 1st antenna of P. japonica the combined length of the joints following the 2nd suture is much smaller relative to the length of the 2nd joint than it is on P. anax. The basale of the mandible bears 4 ventral bristles on P. japonica and only 3 on P. anax. Each lamella of the furca bears 7 claws on P. japonica and 6 claws plus 1 bristle on P. anax. Spatulate bristles on the penultimate joint of the male 1st antenna have not previously been reported in the Polycopidae.