Chromaspirina aliapapillata, Revkova & Revkov, 2022

Revkova, Tatiana N. & Revkov, Nikolai K., 2022, Chromaspirina aliapapillata sp. nov. (Nematoda, Desmodorida) from Donuzlav Bay (Crimea, Black Sea), Zootaxa 5169 (5), pp. 485-493 : 487-492

Chromaspirina aliapapillata sp. nov.

( Figure 2–4 , Table 1 )

Type material. 9 males and 4 females. Glycerin slides. Holotype was collected from station 3 on the slide Meib.3.N.h.; paratypes: 8 males on slides Meib.4.N.p.–Meib.11.N.p. and 4 females on slides from Meib.12. N.p.–Meib.15.N.p. deposited in the collection of the Institute of Biology of the Southern Seas of RAS, Sevastopol, Russia.

Type locality and habitat. Donuzlav Bay , Crimea, Black Sea. Holotype from station 3: N45.320340°, E33.013790°, wate r depth 2 m, 18.5‰ salinity, sediment—soft sandy silt with detritus and with the presence of a persistent smell of hydrogen sulfide.

Etymology. The species name “ aliapapillata ” is derived from the latin “ alius” (= different) and refers to presence of precloacal supplements with different shapes in males.

Description. Male. Body long, cylindrical and slender. Cuticle with transverse striae, less obvious in head region than in tail region. Annulation surrounds the amphid partly. Inner labial papillae not visible. Circle of six outer labial setiform sensillae and four cephalic setae (5–6 µm long) located at the mid-level of the amphids. Amphideal fovea (35.3–43.8% of corresponding body diameter) round, spiral with 1.2 turns, its posterior end located between the first two body annuli. A total of 8 cervical setae (3–4 µm long): one ventro-lateral pair and one dorso-lateral pair; one latero-dorsal pair and one latero-ventral pair. Small pores visible on the ventral and dorsal sides scattered throughout the body ( Fig. 4 F ).

Buccal cavity conical with two dorsal teeth (one smaller and one medium-sized) and two smaller subventral teeth. Stoma with a crown of cheilorhabdia in the cheilostoma. Pharynx muscular with pyriform terminal bulb, lumen not cuticularized. Secretory-excretory system not observed. Nerve ring at 52.3–62.9% of pharynx length. Cardia 10–14 µm long, not surrounded by intestinal tissue.

Reproductive system monorchic, with outstretched testis situated to the left of intestine; sperm cells large, from globular to elongated in shape (5–17 μm in length). Spicules short, arcuate with well developed round capitulum; velum present. Gubernaculum mostly straight and simple. A total of 17 to 21 precloacal supplements of which one near cloaca is cup-shaped and the rest are with curved tubes ( Fig. 3 D , Fig. 4 L, K ). O ne male (Meib.11. N.p.) with two cup-shaped precloacal supplements near cloaca. Tail conico-cylindrical, with minute subventral setae (barely visible under light microscope); only the small tip is smooth. Caudal glands not visible. Spinneret present.

Females. Similar to males. With 12 cervical setae (3–4 µm long) visible in one paratype female: one ventrolateral pair and one dorso-lateral pair; two latero-dorsal pairs and two latero-ventral pairs. Reproductive system didelphic, amphidelphic with reflexed ovaries, located entirely to the left of the intestine; anterior ovary 236–260 μm long and posterior one 155–331 μm long. Vagina cuticularized, with well developed sphincter muscle; vulva situated at 53.8–59.9% of total body length from the anterior end. Three caudal glands present.

Diagnosis. Chromaspirina aliapapillata sp. nov. is characterized by a slender body (a= 53.5–83.2), the body length of 1765–2249 µm; buccal cavity with two dorsal teeth; spiral amphids with 1.2 turns; position of the cephalic setae at the posterior edge of the non-annulated head region; tail conico-cylindrical; presence of 17 to 21 precloacal supplements of which one or two are cup-shaped and rest curved tubes.

Differential diagnosis. According to the morphological features Chromaspirina aliapapillata sp. nov. differs from Chromaspirina species by the position of teeth: two dorsal and two subventral; shape (one or two cupshaped near cloaca and the rest curved tubes) and number of precloacal supplements. The new species resembles Ch. vanreuselae Verschelde & Vincx, 1996 , Ch. chabaudi Boucher, 1975 , Ch. multipapillata Jayasree & Warwick, 1977 , Ch. pontica Filipjev, 1918 , Ch. parapontica Luc & De Coninck, 1959 and Ch. inglisi Warwick, 1970 .

Ch. aliapapillata sp. nov. differs from Ch. vanreuselae by shorter body (1765–2249 μm vs. 2533–3183 μm), size of the amphids (37.5–46.6% vs. 36–37% of corresponding body diameter), shorter cephalic setae (5–6 μm vs. 12–13 μm), shorter spicules (31–35 μm vs. 54–56 μm) and shorter gubernaculum (15–19 μm vs. 24–33 μm).

The new species differs from Ch. chabaudi by the shorter cephalic setae (6 μm vs. 9–12 μm), shorter pharynx (b= 12.3–16.4 vs. 10.5–11), shorter spicules (31–35 μm vs. 39 μm), absence of four subcephalic setae and position of the cervical setae.

The new species differs from Ch. multipapillata by the shorter pharynx (b= 12.3–16.4 vs. 11.1–12), shorter cephalic setae (6 μm vs. 12–14 μm), size of the amphids (37.5–46.6% vs. 50% of corresponding body diameter), shape of the tail (conico-cylindrical vs. conical) and presence of the cervical setae.

The new species differs from Ch. pontica , Ch. parapontica and Ch. inglisi by shape of the tail (conico-cylindrical vs. conical), absence of the somatic setae, shorter spicules (31–35 μm vs. 55 μm (in Ch. pontica ), 63–80 μm (in Ch. parapontica ) and 48–54 μm (in Ch. inglisi )), and shorter gubernaculum (15–19 μm vs. 45 μm (in Ch. pontica ), 37–41 μm (in Ch. parapontica ) and 22–25 μm (in Ch. inglisi )). It differs from Ch. pontica and Ch. parapontica by the shorter body (1765–2249 μm vs. 2650–2800 μm (in Ch. pontica ) and 2546–4642 μm (in Ch. parapontica )) and from Ch. inglisi by more slender body (a= 54.5–83.2 vs. 38.7–48.8) and shorter pharynx (b= 12.3–16.4 vs. 9.9–11.1).

Figures

FIGURE 2. Chromaspirina aliapapillata sp. nov. A. Entire female. B. Head region. C. Reproductive system. D. Tail region. E. Pharyngeal region. Scale bar: A = 200 μm; C = 50 μm; D, E =20 μm; B =10 μm.

FIGURE 3. Chromaspirina aliapapillata sp. nov. A. Entire male. B. Copulatory apparatus. C. Pharyngeal region. D. Precloacal supplements. E. Tail region. F. Head region. Scale bar: A = 200 μm; E, C = 50 μm; B, D =20 μm; F =10 μm.

FIGURE 4. Chromaspirina aliapapillata sp. nov. A. Entire female. B. Entire holotype male. C. Male1, head region. D. Female, buccal cavity. E. Female, head region. F. Female, bulbus, cardia and pores. G. Female, vulval region. I. Holotype male, spinneret. J. Holotype male, copulatory apparatus and precloacal supplements. K. Holotype male, precloacal supplements. L. Male3, precloacal supplements. M. Male3, posterior region. Scale bar: A, B = 200 μm; F, G, J, M = 20 μm; C, D, E, I, K, L = 10 μm.