Hyalocoecia hyalophyllum Chavtur & Bashmanov 2018, comb. nov.

• Main Authors: Chavtur, Vladimir G., Bashmanov, Alexander G.
• Format: Text
• Language: unknown
• Published: Zenodo 2018
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Ostracoda; Halocyprida; Halocyprididae; Hyalocoecia; Hyalocoecia hyalophyllum; Antarctic; The Antarctic; Pacific; Indian; Seta; Antarc*
• Online Access: https://dx.doi.org/10.5281/zenodo.5959301; https://zenodo.org/record/5959301

Hyalocoecia hyalophyllum (Claus, 1890) comb. nov. (Figs. 33, 34) 1890 Conchoecia hyalophyllum —Claus: 11; 1891 Conchoecia hyalophyllum —Claus: 60; pl. VI, figs. 2–10; pl. VIII, fig. 9; 1896 Conchoecia hyalophyllum —Brady & Norman: 692 1906 Conchoecia hyalophyllum —Müller: 101, pl. XX, figs. 19–26; 1909 Conchoecia hyalophyllum— Fowler: 236, 265, 287; pl XIX, figs. 93–96, 105; pl. XX, figs. 97, 106, 107. 1969a Conchoecia hyalophyllum —Angel: 45–51, figs. 1–3; 1973 Conchoecia hyalophyllum — Poulsen, 1973: 140 –142, fig. 69 a–j; 1993 Conchoecia hyalophyllum —Angel: 162, fig. 55. Examined material . MFFT Professor Kaganovsky , 2010: MIMB 18350 /1—adult male (1.70 mm), station 81, sample 152, 38°00´N– 164°00´E, layer 200–0 m, sounding 4100 m, April 28, 2010; MIMB 18350 /2—adult male (2.72 mm), station 83, sample 154, 39°00´N– 161°00´E, layer 200–0 m, sounding 5200 m, 30 April. Addition description of adult male. Carapace (Fig. 33 A–C). The length is between 1.46–1.72 mm (summary literature data from Müller 1906; Skogsberg, 1920, Poulsen 1973; Deevey 1978a; Angel 1993: 1.50–1.70 mm). The carapace is short, rectangular and does not taper anteriorly. The height is 57–59% of the carapace length. The posterior and ventral margins are almost straight. The left asymmetrical gland opens close to the dorsal corner. The right asymmetrical gland is placed in the postero-ventral corner, and left asymmetrical gland near the posterodorsal corner. Each valve has one lateral gland near the postero-ventral corner and one near the postero-dorsal corner. Gland cells beneath the rostral incisures are absent. Sculpture consists mainly of concentric lines. Frontal organ (Fig. 33 D–F). The capitulum is bent downwards. It is moderate broad, with a slight dorsal concavity and a rounded tip (pointed tip only in specimens described by Angel 1969; 1993). The capitulum surface is extensively covered with small spines in the basal half, but is bare distally. First antenna (Fig. 33D, E, G). The length of the first and the second segments are subequal. Seta-a reaches to about mid-length of the first segment. Seta-c is about equal to the combined lengths of the third, fourth and fifth segments. Armature of seta-e consists of a comb of about 19–23 pairs of small, directed proximally spines and 13– 14 alternated ones (totalling 52–59) (summary literature data from Poulsen 1973; Angel 1993: 20?, 24–25 pairs of spines and 20–30 alternated ones). Lengths of spines are less than the diameter of the seta at the distal part of the comb. Second antenna (Fig. 33 H–L). Seta-b on the first endopodite segment has about six long basal fine filaments (summary literature data from Müller 1906; Poulsen 1973; Deevey 1978a; Angel 1993: with five or six filaments; in Poulsen 1973 only with three posterior and three anterior medium-length filaments). The right clasping organ is right-angled and oblique proximally, slightly swollen and with a spine-like tip. The left clasping organ is moderately thick, not tapered to the end and almost right-angled, with a spine-like tip. Setae-h–j differ in length, but are relatively slim, and slightly tapered towards to their ends. Seta-g is about twice as long as setae-h–j. Mandible (Figs. 33M; 34 A–F). The epipodite has a slightly developed seta on the verruca (in Poulsen 1973 without a seta). The ventral margin of the first endopodite segment bears two setae (one long and one mediumlength). The disto-dorsal seta of this segment is plumose. The toothed edge of the coxale endite is armed with ten teeth; the distal tooth-list and proximal tooth-list are with 14 and 15–16 teeth, respectively (in Poulsen 1973: 9–11, 14 and 16–24 teeth, respectively). The masticatory pad is armed with three rounded flaps, four flat spines and about 24–40 seta-like filaments (only 19 in specimens described in Poulsen 1973). Maxilla . The first endopodite segment has six anterior and three posterior setae. Anterior setae are located along all of its margin. The distal edge of the first endopodite segment is armed with two to four long spines (five in Poulsen 1973). Fifth limb . The basal segment has a proximal group of three or four setae ventrally, a medio-lateral group of two and a distal group of three setae. Laterally, the basal segment is with a seta and has a distal seta dorsally (vestige of the exopodite), which reaches or barely extends beyond the end of the limb. The first endopodite segment bears two ventral setae and one dorsal seta. Sixth limb (Fig. 34G). The coxale has two long plumose setae. The basale bears four ventral setae: two proximal setae (one long and plumose and one short and bare) and two short distal setae, and is without a lateral seta. The exopodite seta barely reaches the proximal suture of the first endopodite segment. Caudal furca (34L). Claws are relatively long and slim. An unpaired seta is present and is longer than the eighth pair of claw setae. Copulatory appendage (Fig. 34I, K). It is elongated, broader at the middle, and tapered to a rounded end. The distal seta is thin. The appendage is large, triangular and with a rounded tip. The limb has four or five oblique muscle bands. Remarks. Morphology of our specimens is generally similar to those reported in the literature (Müller 1906; Poulsen 1973; Deevey 1978a; Angel 1993), but differs by fewer spines on the armature of seta-e of the first antenna in the male. Distribution. This s pecies has been recorded from all oceans: in the Atlantic Ocean it is known from 63°N to 55°S, in the Indian Ocean between 5°N and 35°S, and in the Pacific Ocean in a range of about 10°N–56°S at depths from 100–300 m to 3100–3300 m. In our material this species was collected from two areas: in the north-western Pacific between 38°–39°N at depths of 0–200 m, and in the north-eastern Pacific between 18°–31°N at depths of 200–500 m (Fig. 28). : Published as part of Chavtur, Vladimir G. & Bashmanov, Alexander G., 2018, Pelagic ostracods of the new subtribe Conchoeciina (Ostracoda, Crustacea) from the North Pacific, pp. 1-127 in Zootaxa 4516 (1) on pages 67-70, DOI: 10.11646/zootaxa.4516.1.1, http://zenodo.org/record/2609394 : {"references": ["Claus, C. (1890) Die Gattungen und Arten der Mediterranen und Atlantischen Halocypriden nebst Bemerkungen uber die Organisation derselben. Arbeiten aus der Zoologischen Institute der Universitt Wien und der Zoologischen Station in Triest, 9, 1 - 34. [in German]", "Poulsen, E. M. (1973) Ostracoda-Myodocopa. Part IIIB. Halocypriformes-Halocypridae. Conchoeciinae. Dana Report, 84, 1 - 223.", "Muller, G. W. (1906) Ostracoda. Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition auf dem Dampfer \" Faldivia \" 1898 - 1899, 8 (2), 29 - 154.", "Skogsberg, T. (1920) Studies on marine ostracods. Part 1. (Cypridinids, halocyprids and polycopids). Zoologiska Bidrag fran Uppsala, Supplement Band 1, 1 - 784.", "Deevey, G. B. (1978 a) A taxonomic and distributional study of the planktonic ostracods collected on three cruises of the \" Eltanin \" in the South Pacific and the Antarctic Region of the South Pacific. Biology of the Antarctic Seas, FIII Antarctic Research, 28 (3), 43 - 70.", "Angel, M. V. (1993) Marine planktonic ostracods: keys and notes for identification of the species. In: Synopses of the British Fauna. New Series. Fol. 48. The Linnean Society of London and Estuarine and Coastal Sciences Association, Field Studies Council, Shrewsbury, pp. 1 - 240."]}