Conilia sinensis Chen and Guo 2015
Creators: name: Lee, Hyo Jin
name: Rho, Heegab Lee and Hyun Soo
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Enoplea
Enoplida
Ironidae
Conilia
Conilia sinensis

description: Conilia sinensis Chen and Guo, 2015
(Figs. 1-3; Tables 1, 2)
Conilia sinensis Chen and Guo, 2015, p. 152, Figs. 1, 2.
Material examined. One male (MABIK NA00157737), in glycerin on HS slide, was deposited in the nematode collection at the specimen conservation room of the Marine Biodiversity Institute of Korea (MABIK), Seochun, Korea. Three males (KIOST NEM - 1 - 2408, KIOST NEM - 1 - 2650, KIOST NEM - 1 - 2651) and Four females (KIOST NEM - 1 - 2652, KIOST NEM - 1 - 2653, KIOST NEM - 1 - 2654, KIOST NEM - 1 - 2655), in glycerin on HS slide, were deposited in the nematode collection at the specimen conservation room of the Bio-Resources Bank of Marine Nematodes (BRBMN), East Sea Research Institute, Korea Institute of Ocean Science & Technology (KIOST), Korea. All the specimens were collected from Mageompo Beach, Nam-myeon, Taean-gun, Chungcheongnam-do, Korea, 9 June 2018 (leg. H. Lee).
Habitat. Intertidal fine sand beach (36°37′07.32″N, 126° 17′10.27″E).
Measurements. See Table 1 for detailed measurements and morphometric ratios.
Description. Males. Body cylindrical and slender (2,349 - 2,586 μm long), gradually tapering towards posterior end of body (Fig. 1A). Maximum body diameter at mid body level 34 - 38 μm. Cuticles smooth. Head end compressed, lip region well-developed and slightly swelled on both sides, with six papilliform inner labial sensilla (Fig. 1C). Head diameter 30 μm wide, with remarkable constriction at posterior to cephalic setae. Six outer labial setae (8 - 10 μm long) and four relatively long cephalic setae (22 - 26 μm long) arranged in a single circle. Buccal cavity divided into two parts: anterior one cup-shaped and posterior one strongly cuticularized tube-shaped (Figs. 1C, 3A). Three solid curved claw-like teeth lie in anterior part of buccal cavity, with small cuticular denticles in a row at edges (Fig. 3B). Amphideal fovea not observed. Anterior pharynx region surrounding buccal cavity slightly inflated and posterior region general cylindrical without swelling. Pharynx cylindrical (409 - 429 μm long), corresponding body diameter 31 - 33 μm. Nerve ring located on 146 - 167 μm from anterior end, corresponding body diameter 31 - 33 μm, situated at 36 - 39% of pharynx length (Fig. 1B). Reproductive system diorchic; two testes opposed and outstretched. Spicule (89 - 99 μm long) single and elongated, with transversely organized thick striated tissue (Figs. 1E, 3D). Telamons (21 - 27 μm long) paired, strongly rib-shaped, distally with bifurcated hook-like structures and proximally with rounded changeable projection. Gubernaculum (21 - 25 μm long) single, with slightly curved thin strip. A precloacal supplement (2 μm long) shows simple ventral swelling, situated at 14 - 18 μm in front of cloacal opening (Figs. 1D, 3D). Tail (106 - 125 μm long) conicocylindrical, slightly ventrally bent; distal part slightly swollen with two terminal setae. A conspicuous ventral swelling appeared in middle of tail (Figs. 1D, 3C).
Females. Similar to males in general characteristics, but differ in several dimensions, tail shape, and sexual characteristics (Figs. 2A, B, D, 3F, G). Body length 2,141 - 2,196 μm; cylindrical body slightly tapered toward posterior end. Maximum body diameter 46 - 53 μm. Reproductive system didelphic. Two reflexed equally developed ovaries; anterior ovary situated on right side of intestine, posterior one on right side of intestine. Vulva 1,229 - 1,276 μm from anterior end, situated at 57 - 59% of total body length (Figs. 2C, 3E). Tail conical, straight, without setae or swelling. Tail 132 - 144 μm long, about 5.1 - 5.8 times of anal body diameter (Figs. 2E, 3H).
Amphideal fovea Absent Present Absent Absent
Spicule length 112 60 - 64 87 - 100 89 - 99
All measurements are in μm.
Remarks. The genus Conilia was established by Gerlach in 1956 with the type species, Conilia divina Gerlach, 1956. The genus is characterized by having a cuticularized elongated tubular buccal cavity, three claw-like teeth of different sizes and an oblique serrated plate, papilliform inner labial sensilla, and setiform outer labial and cephalic sensilla. The genus Conilia is composed of only three valid species so far (C. divina Gerlach, 1956, C. monospiculata Aryuthaka, 1989 and C. sinensis Chen and Guo, 2015). Morphological and ecological characteristics of the genus Conilia including the Korean C. sinensis are given in Table 2. Conilia sinensis was firstly described from Dongshan Island in the East China Sea. Conilia sinensis is distinguished from other species of the genus by having a relatively long body length, a well-developed buccal cavity, single spicule with transversely striation, rib-shaped telamons, and single precloacal supplement. Conilia sinensis is most like C. divina by possessing a long and striated spicule and the absence of amphideal fovea. However, C. sinensis significantly differs from C. divina by the longer body length (1,956 - 2,399 μm vs. 1,535 μm in males; 1,883 - 2,080 μm vs. 1,630 μm in females), the longer telamons length (25 - 28 μm vs. 12 μm), and the number of precloacal supplements (1 vs. 4). Moreover, C. sinensis has a conspicuous ventral swelling in the middle of the tail, a feature not shared by C. divina.
Conilia sinensis is also clearly distinguished from C. monospiculata by the longer body length (1,956 - 2,399 μm vs. 1,529 - 1,990 μm in males; 1,883 - 2,080 μm vs. 1,689 - 2,025 μm in females), the absence of amphideal fovea (present in C. monospiculata), the presence of single precloacal supplement (absent in C. monospiculata), and the longer striated spicule (87 - 100 μm vs. 60 - 64 μm).
The present Korean specimens of C. sinensis agree well with the original description in general features, especially in the detailed structure of copulatory systems in males, the presence of single precloacal supplement, and ventrally bent tail with single ventral swelling in the middle of the tail. However, the Korean specimens differ from original description by having a longer overall body length (2,349 - 2,568 μm vs 1,956 - 2,339 μm in males; 2,141 - 2,196 μm vs 1,883 - 2,080 μm in females) and slightly shorter tail length (c = 20.6 - 24.0 vs. c = 15.8 - 19.8 in males; c = 14.9 - 16.5 vs. c = 13.8 - 16.5 in females).
All measurements are in μm.
Distribution. China (Chen and Guo, 2015) and Korea (Present study).
description: Published as part of Lee, Hyo Jin & Rho, Heegab Lee and Hyun Soo, 2023, Two new records of free-living marine nematodes of the family Ironidae de Man, 1876 (Nematoda: Enoplida) from Korea, pp. 55-67 in Journal of Species Research 12 (1) on pages 57-62, DOI: 10.12651/JSR.2023.12.1.055, http://zenodo.org/record/12753323