Pseudopolycope (Pseudopolycope) andeep, Karanovic, Ivana & Brandão, Simone Nunes, 2013

Karanovic, Ivana & Brandão, Simone Nunes, 2013, Pseudopolycope (P.) andeep sp. nov. from the deep Southern Ocean (Crustacea, Ostracoda, Cladocopina), Zootaxa 3692 (1), pp. 123-135 : 125-132

Pseudopolycocope (Pseudopolycope) andeep sp. nov.

( Figures 1–5 )

Etymology. The species is named after the project “ANDEEP-SYSTCO” ( ANtarctic benthic DEEP-sea biodiversity: colonisation history and recent community patterns – SYSTem COupling).

Type material: holotype Ƥ (ZMH K-42871, dissected on one slide); paratype juvenile Ƥ (ZMH K- K-42873, dissected on one slide); paratype juvenile Ƥ (ZMH K-42872, mounted on SEM stub) from R.V. Polarstern, ANDEEP-SYSTCO I cruise, PS 0 71, ANT XXIV-2, station 17-11, 22/12/2007, EBS trawled from 70° 5.13' S, 3° 23.50' W, 1724 m (EBS on ground) to 70° 4.64' S, 3° 22.21' W, 2063 m (EBS from the bottom).

Diagnosis. Oval carapace with a small rostral incisure frontally. Antero-ventrally surface with several striaelike ornaments. Antennula with five bristles on terminal segment, penultimate segment with one short bristle. Protopod of antenna with total of nine long and one short bristle. Exopod of the same appendage with three bristles on the terminal segment. Exopod of mandibula with one strong bristle with round, open tip, one additional bristles laying in its basis and a wart-like process. First segment of mandibular palp with four bristles; second segment ventrally with three, dorsally with two bristles. Endopod maxillula 3-segmented, terminal segment with four bristles. Endopod of fifth leg with segment and distal bristle; exopodal segment with five bristles. Uropodal lamellae with seven claws; structures between claws complex.

Description. Adult female (holotype): Carapace oval in lateral view ( Figure 1 A), with evenly rounded dorsal and ventral margins. Dorsal margin with prominent flange, ventral with thin, translucent membrane. Anterior margin with small incisure, and with prominent dull rostrum. Surface generally smooth, except in antero-ventral region where covered with striae-like ornaments. Surface with two types of pores: one with bristles coming out, others smaller and without bristles ( Figures 5 A, B). Adductor muscle scar consisting of five, circularly arranged scars. L of carapace (measured in a straight line from the tip of the rostrum to the posterior margin) equalling 1.45 mm, H (measured medially in the straight line) equalling 88% of total L.

Bellonci Organ ( Figure 1 B): Consisting of two bristles proximally fused. Fused part equalling less than third of bristles L. Both bristles covered with spiky setulae.

Antennula ( Figures 1 C, D, E): 5-segmented, but division between second and third segment not prominent. Segment two, as well as fused segment 3–5 densely covered with setulae, dorsal ones on second segment and some ventral on fused segment 3–5 much longer than other. Second segment with one dorsal bristle which slightly exceeding distal end of following segment. Third segment (representing fused segments 3–5) without any brisltes. Fourth segment (segment 6) with one dorsal, thin bristle, this segment not so hirsute like previous ones. Terminal segment (representing fused 7th and 8th segments) with total of five distal bristles, all long, ringed and sparsely covered with short setulae. Third segments clearly wider proximally than distally. Its L: W ration equalling 2: 1 (L measured along central axis, W measured at widest part). L: W ratio of fourth segment equalling 1.5: 1. L ratio between second, third and fourth segments equalling 2.7: 2.5: 1.

Antenna ( Figures 1 F–J): Basis broad and without any bristles, dorsally hirsute. Exopod 9-segmented, and each segment bearing one long ringed bristle, except last one which carrying three bristles – two long, one short and thin. First exopodal segment dorsally with long prominent setulae. Each of the ringed bristles with short and sparse setulae. Bristles become smooth around 2/3 of their length. Endopod 3-segmented. First segment on one antenna with small spine (arrow pointed on Figure 3 E), second segment with one dorso-medial bristle and four long distal bristles. Terminal segment with four long bristles. All bristles covered with sparse and short setulae, except for two bristles (one on the second segment, other on the third) which have longer setulae close to their bases, which latter become as short as on other bristles. All bristles become smooth after second third of their L.

Mandibula ( Figures 4 C, G, 5D): Coxa with two large teeth, one marginally serrated. Between large teeth four smaller teeth present, two (which are situated close to the large tooth with serrated margin) with split tips. Basis with four spinous bristles situated ventrally, one of which much weaker than other three. Same segment with one dorsal spinous bristle, reaching first third of first endopodal segment. Exopod prominent, cylindrical and 1- segmented, distally carrying one strong bristle with rounded and open tip, one much shorter pappose bristle, and one small wart-like extension. Bristle with cylindrical tip with several long and strong setulae. Endopod 2- segmented; terminal segment not completely separated from penultimate one. First segment with three spinous bristles ventrally and two spinous bristles dorso-distally of which one with much longer setulae proximally. First segment very densely covered with short, stiff setulae. Terminal segment with two strong spinous bristles, one almost claw-like and both covered with long and stiff setulae.

Maxillula ( Figures 2 C, D): Praecoxa and coxa not clearly separated. Three endites present: first one with five short, strong bristles, all with stiff (some with long) setulae; second endite with three spinous bristles; third with two spinous bristles. Bristles on endites two and three longer and more slender than bristles on endite one. Coxa also with another five bristles, not belonging to any of the endites. Mote proximal three of those five bristles shorter than two distal ones; all five bristles spinous. Basis dorsally with a knee-like structure which hirsute, ventrally basis with two spinous bristles, one much shorter than other. Endopod three segmented: first segment with one ventral bristle, second segment with three ventral and two dorsal bristles; terminal segment with total of four bristles. All bristles on endopod long and spinous. Endopodal segments sparsely covered with short, stiff setulae. Exopod proximally with two rows of long and stiff setulae. Exopod distally with total of nine bristles, eight being almost subequally long, ringed and covered with short setulae, one much shorter.

Fifth limb ( Figures 2 E, F): Coxa hirsute with two proximal and two distal, pappose bristles. Basis strongly hirsute and with total of seven bristles: three situated dorsally one of which covered with very long and stiff setulae, two being pappose; another three bristles situated ventrally, one of which being slender and smooth, other two much stronger and pappose; one bristle situated distally on basis and this bristles being long and covered with stiff setulae. Endopod 1-segmented, very strongly hirsute (spiky appearance), distal bristle fallen off during dissection. Exopod 1-segmented and almost square-shaped and with five bristles, all being covered with strong setulae. Entire fist limb extremely hirsute (only small portion of setulae shown on Figure 2 E). Epipod with about 16 plumose bristles.

Uropodal lamellae ( Figure 3 A): Each lamella with seven strong claws. Spines on first claw shorter than on latter claws. Each claw with a thin chitinous membrane marginally. Structures between all claws except sixth and seventh complex, bifurcate and with one pappose bristle. Structure between sixth and seventh claw simple. One short, claw-like extension following seventh claw. Postero ventrally body with a strong, hirsute spine (arrow pointing on Figure 3 A and B), while postero-dorsally with rows of spine-like setulae. Lamellae also covered with setulae, some slender, some stiff. Genital field quite complex with some chitinous structures, most prominent one situated on the basal part of lamellae (arrow pointing on Figure 3 A), each with quite short spines.

Males: Unknown.

Juvenile female (paratype): Carapace oval in lateral view ( Figure 3 C), with less pronounced frontal rostrum, but with more prominent incisure laying bellow the rostrum. Dorsal margin with prominent flange, ventral with thin, translucent membrane, Surface generally smooth, except in antero-ventral region where covered with striaelike ornaments. Surface with two types of pores: one with bristles coming out, others smaller and without bristles ( Figure 5 A, B). L of carapace (measured in a straight line from the tip of the rostrum to the posterior margin) equalling 1.14 mm, H (measured medially in the straight line) equalling 90% of total L.

Bellonci Organ ( Figure 3 D): Consisting of two bristles proximally fused. Fused part shorter than in adult. Both bristles covered with spiky setulae.

Antennula: Same as in adult.

Antenna ( Figures 3 E, 4A, B): Basis broad and without any bristles, dorsally hirsute. Exopod 9-segmented, and each segment bearing one long ringed bristle, except last one which carrying three bristles – one very long, one medially long, and one short and thin. First exopodal segment dorsally with long prominent setulae. Each of the ringed bristles with short and sparse setulae. Bristles become smooth around 2/3 of their length (dotted line on Figure 1 J). Endopod 3-segmented. First segment without any bristles, second segment with one dorso-medial bristle and five long distal bristles. Terminal segment with four long bristles. All bristles covered with sparse and short setulae, except for two bristles (one on the second segment, other on the third) which have longer setulae close to their bases, which latter become as short as on other bristles. All bristles become smooth after second third of their L (dotted line on Figure 1 H).

Mandibula ( Figures 2 A, B. 5D): Coxa with two large teeth, one marginally serrated and a rake-like structure situated between serrated toot and its neighbouring bifurcate tooth (arrow pointing on Figure 5 D). Four smaller teeth also present, two (which are situated close to the large tooth with serrated margin) with split tips. Basis with four spinous bristles situated ventrally, one of which much weaker than other three. Same segment with one dorsal spinous bristle, reaching first third of first endopodal segment. Exopod prominent, cylindrical and 1-segmented, distally carrying one strong bristle with rounded and open tip, one much shorter pappose bristle, small wart-like extension not prominent like in adult. Bristle with cylindrical tip with several long and strong setulae. Endopod 2- segmented; terminal segment not completely separated from penultimate one. First segment with three spinous bristles ventrally and two spinous bristles dorso-distally of which one with much longer setulae proximally. First segment very densely covered with short, stiff setulae. Terminal segment with two strong spinous bristles, one alsmost claw-like and both covered with long and stiff setulae.

Maxillula ( Figure 4 D–F): Praecoxa and coxa not clearly separated and distinction between endites difficult. Basis dorsally with a knee-like structure which hirsute, ventrally basis with two spinous bristles, one much shorter than other. Endopod three segmented: first segment with one ventral bristle, second segment with three ventral and two dorsal bristles; terminal segment with total of four bristles. All bristles on endopod long and spinous except one dorsal bristle on second segment which short. Endopodal segments sparsely covered with short, stiff setulae. Exopod proximally with two rows of long and stiff setulae. Exopod distally with total of nine bristles, eight being almost subequally long, ringed and covered with short setulae, one much shorter.

Fifth limb: Same as in adult, here distal bristle on endopodal segment present, long, and spinous.

Uropodal lamellae ( Figures 3 F, 5F): Each lamella with six strong claws. Spines on first claw shorter than on latter claws. Structures between all claws except fifth and sixth complex, bifurcate and with one pappose bristle. Structure between fifth and sixth claw simple. Two short, claw-like extensions following sixth claw. Postero ventrally body with a strong spine (arrow pointing on Figure 5 F), while postero-dorsally with rows of spine-like setulae. Lamellae also covered with setulae, some slender, some stiff. Genital field not developed.

Figures

FIGURE 1. Pseudopolycope (Pseudopolycope) andeep sp. nov. holotype, female: A, left valve, external view; B, Bellonci Organ, one bristle broken; C, antennula, long bristles not shown; D, distal part of antennula; E, antennula, indicating the length of bristles in comparison to the appendage; F, basis, endopod and exopod of antenna, long bristles not shown; G, first (distal part only), second and third segments of the endopod of antenna; H, endopod of antenna, indicating the length of bristles in comparison to the appendage, dotted line indicates where the setulae stop; I, exopod antenna, only proximal part of bristles shown; J, exopod of antenna, indicating the length of the bristles in comparison to the appendage, dotted line shows where the setulae stop. Scales = 0.1 mm.

FIGURE 2. Pseudopolycope (Pseudopolycope) andeep sp. nov. holotype, female: A, mandibula, without coxa; B, distal part of mandibular coxa; C, praecoxa and coxa of maxillula; D, part of coxa, entire basis, endopod and exopod of maxillula; E, fifth limb, epipod only partially drawn, brisltes on exopod not shown, endopod lacking distal bristle; F, exopod maxillula. Scale = 0.1 mm.

FIGURE 3. Pseudopolycope (Pseudopolycope) andeep sp. nov. A, B, holotype, female; C – F, paratype, juvenile female: A, uropodal lamella, left arrow indicating one prominent chitinous structure, right arrow indicating postero-ventral spine-like extension of the body; B, postero-dorsal and party postero-ventral part of the body, also two last claw-like extensions of both uropodal lamellae drawn in a dotted line, arrow indicating postero-ventral spine-like extension of the body; C, RV, internal view; D, Bellonci Organ; E, antenna, bristles not shown, arrow indicating short spine like process on the first segment of the endopod. Scales = 0.1 mm.

FIGURE 4. Pseudopolycope (Pseudopolycope) andeep sp. nov. paratype, juvenile female: A, exopod of antenna, bristles only partially illustrated; B, endopod of antenna; C, part of the mandibular coxa; D, maxillula, two distal segments of the endopod missing; E, two distal segments of the endopod maxillula; F, distal part of the exopod maxillula; G, mandibula, coxa missing. Scale = 0.1 mm.

FIGURE 5. Pseudopolycope (Pseudopolycope) andeep sp. nov. SEM photographs, paratype, juvenile female: A, large pore with one (probably) sensila coming out; B, comparison of two types of pores on the shell surface; C, striae-like ornamentation antero-ventrally on the shell; D, distal part of mandibular coxa, arrow indicating small rake-like process; E, first segment of antennula showing stiff setulae covering the entire appendage; F, postero-ventral part of the uropodal lamellae, arrow indicating spine-like extension of the body.