Deeveyoecia, Chavtur & Angel, 2011

Chavtur, Vladimir G. & Angel, Martin V., 2011, Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857, Zootaxa 2857 (1), pp. 1-87 : 32-33

Key to species of Deeveyoecia (excluding D eeveyoecia n. sp 2 aff. C. arcuata )

1a. h-seta on A2 endopodite has a proximal filament and a central protuberance; the i- and j-setae are about double the length of the first endopodite segment.............................................................. .. D. bathyrotundata

1b. h-seta on endopodite of A2 has a proximal filament but no central protuberance; the i- and j-setae are <2 times the length of first endopodite segment................................................................................ 2

2a. Male armature of the e-seta of A1 consists of 12 pairs of spines, the seta is about twice as long as limb; h-seta on endopodite of A2 has short filament; the i- and j-setae are ≤1.5x the length of first endopodite segment.......... D. n. sp 1 aff. C. arcuata

2b. Male armature of the e-seta of A1 consists of 9 pairs of spines; the seta is about 1.5x length of limb; h-seta on endopodite of A2 has long proximal filament; i- and j-setae are>1.5x length of first endopodite segment....................... D. arcuata

JURYOECIA Chavtur & Angel n.gen.

Synonymy:

1962 Conchoecia —Rudjakov, p. 185 (part).

1977a Conchoecia —Chavtur, p. 146 (part).

1981 Conchoecia skogsbergi species complex—Gooday p. 159 (part).

1986 Metaconchoecia —Kempf, p. 498 (part).

1992 Metaconchoecia —Kock, p. 68 (part).

Etymology. The name is derived from “Jury” to honour Jury Rudjakov who has made major contributions to halocyprid taxonomy and zoogeography (it was he who originally described Conchoecia abyssalis ), and “-oecia” derived from the Greek word “οƖκοσ” meaning house, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.

Type species. Juryoecia distoglandula Chavtur & Angel n. sp.

Composition. The genus includes two species:

Conchoecia abyssalis ( Rudjakov 1962)

Juryoecia distoglandula Chavtur & Angel n. sp., described below

Differential diagnosis. Deep bathypelagic to abyssopelagic species; males (1.60–1.90 mm) are longer than females (1.30–1.60 mm). Carapaces quite elongate; CH = 45–56%CL with maximum height generally posterior to midlength. Sculpturing of fine longitudinal lines evident on carapaces of most specimens. LAG 19–40%CL behind the tip of rostrum. RAG opens very close to the PDC. Male A1 a-seta with two accessory filaments near its base; eseta armature 9–12 pairs of long slim spines.

Description. Males. Carapace. The length range of the described species is 1.60–1.90 mm. The carapace is slightly elongated with a maximum height of 50–56% (45% in J. abyssalis ) that occurs in the posterior half (rarely at midlength). The LAG opens 19–40%CL behind the tip of the rostrum. The RAG opens on the posterior margin just below the posterior dorsal corner and 3–4% CH below the hingeline. The rostrum is large, Lrost being 8– 10%CL. There is a faint sculpturing of straight lines running approximately parallel to the ventral and dorsal margins in J. abyssalis . There is no sculpturing in male J. distoglandula (but there is in the females).

Frontal organ. The capitulum is relatively short, narrow or moderately broad, and slightly concave; it barely extends beyond the end of the A1.

First antenna. The limb is 3x the length of the capitulum of the frontal organ. The a-seta does not extend beyond the proximal margin of the limb and has two filaments inserted close to its base. The c-seta ranges from being just longer, to 1.5x the combined length of the third, fourth and fifth segments. The armature of the e-seta consists of 9–12 pairs of long, thin spines, and the seta is 1.7–1.8x the length of the limb. The d-seta is shorter than the e-seta.

Second antenna. The exopodite is relatively slim and long, 66–80% the length of the protopodite. The sensory h-, i- and j-setae range from 20–50% of the length of the g-seta, which is 1.2x the length of the protopodite, 1.5– 1.8x the exopodite, and 4–5x the length of the first endopodite segment. The f- and g-setae are slightly flattened and pointed. The h-seta is undivided. The c- and d-setae are slim and short, and there is a minute e-seta. The hook appendages are curved and terminally rounded. The left hook is the smaller, and its distal part is only slightly curved.

Mandible ( Fig. 2A, B ). The exopodite is either minute ( J. distoglandula ) or quite small ( J. abyssalis ); it carries a long, stout seta that is either covered with short setules or with a dense covering of long setules. The coxale is short and about half the length of the endopodite.

Copulatory appendage. The length of the appendage is 28–33%CL. It is straight and parallel-sided with a rounded tip. There are 6–7 oblique muscle bands (number only known for J. abyssalis ).

Females. Carapace. ( Fig. 5 ) The length range is 1.30–1.60 mm. As in the male, the carapace is slightly elongate, with its maximum height (50–53%CL) either just posterior to or at midlength. The LAG opens 21–41%CL behind the tip of the rostrum. The RAG opens on the posterior margin immediately below the posterior dorsal corner (2–5% CH). The rostrum is large, Lrost being 7–10%CL. There is a faint sculpturing of longitudinal striae in the females of both species.

Frontal organ. The capitulum is scalpel-like, with a rounded tip; it is a little broader than the shaft and is slightly down-curved. The shaft is unsegmented and is fused to the capitulum. The frontal organ is 1.5x the length of the A1.

First antenna. The a-seta carries proximally a short additional filament. The e-seta is about 2.3–2.5x the length of the limb, and 2.5–2.6x the lengths of the sensory setae. There is a row of minute setules along its trailing edge.

Second antenna. The exopodite is relatively thin and long, about 83–90% the length of the protopodite. The terminal setae are flattened, pointed and subequal; they are about 88–95% the length of the exopodite, 75–80% of the protopodite and 3–4x as long as the first endopodite segment. The h-seta is simple and carries no supplementary filament.

Mandible. The structure of this limb is similar to that of the male.

Comparisons. Juryoecia is most similar to Deeveyoecia . Table 5 summarizes the characters that discriminate most clearly between the two genera.

Distribution. Pacific Ocean: area of the Kurile-Kamtchatka Trench ( Rudjakov 1962; Chavtur 1977a, b, c, 1992), Aleutian Trench ( Chavtur 1992), Mariana, Bougainville and Kermadec Trenches ( Rudjakov 1962) and China Seas ( Chen & Lin 1994, 1995). Its depth range is 3000–9000m. Recent plankton collections from depths of 4000–5000m in the southern sector of the Sargasso Sea (RV Ron Brown cruise 0603, April 2006) contained a few individuals that when examined in detail will almost certainly prove to belong to this genus.

Figures

FIGURE 2. Basal segments of the mandibles of eleven species in the tribe Metaconchoeciini, showing the variations in the extent to which the exopodite is developed; in some species there is a process on which a pappose seta is inserted (indicated by *), but in other species there is no process and only the seta is present. A, Juryoecia distoglandula; B, J. abyssalis; C*, Deeveyoecia bathyrotundata; D*, Rotundoecia teretivalvata; E, Clausoecia pusilla; F*, Vityazoecia goodayi; G*, Metaconchoecia crassiseta; H*, Kyrtoecia kyrtophora; I, Muelleroecia glandulosa; J*, Nasoecia nasotuberculata; L, Austrinoecia isocheira. (Note: the mandibles are not sexually dimorphic, so the sex of the specimen drawn does not have to be specified).

FIGURE 5. Carapace outlines of females of the various forms of Muelleroecia macromma reported in the literature reproduced at identical scales. A, sensu strictu (Müller 1906a); B, M. sp.1 aff. C. macromma Deevey 1974; C, M. sp.2 aff. C. macromma Deevey 1982; D, M. sp.3 aff. C. macromma Poulsen 1973; E, M. sp.4 aff. C. macromma Angel 1981b.