Gomphionema setiforme, Huang & Shi & Wang & Xu, 2021
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publication ID |
https://doi.org/ 10.11646/zootaxa.5016.4.2 |
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publication LSID |
lsid:zoobank.org:pub:AB86B403-953C-48E4-9A03-BF9DCE7DAC9A |
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persistent identifier |
https://treatment.plazi.org/id/03BB8863-E67A-0975-039A-FF1CFEE570CF |
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treatment provided by |
Plazi |
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scientific name |
Gomphionema setiforme |
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sp. nov. |
Gomphionema setiforme sp. nov.
( Figs 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 ; Table 1)
Diagnosis. Body small, 716–902 μm long, a=18.7–22.6; cuticle punctated without lateral differentiation and cu- ticular pores; cephalic sensilla about 2 μm long; spiral amphid in 4 turns; cuticularized buccal cavity about 20 μm long, with a large and cuticularized dorsal tooth; pharynx with posterior bulb, 130-141 μm long; tail conical, 55-66 µm long; spicules curved, about 28 μm long; gubernaculum knife-like without dorsal apophysis; and 11 cup-shaped precloacal supplements.
Type material. Holotype: one male on slide MBM286822 View Materials . Paratypes: one female on MBM286823 View Materials , two females and one juvenile on MBM286824 View Materials , and one female on MBM286825 View Materials .
Type locality and habitat. Intertidal zone in the South China Sea (23°25'34''N, 116°51'15''E), where the species was found from muddy sediment in Laichang Ferry of Shantou City , Guangdong Province GoogleMaps .
Etymology. The Latin adjective setiformis (bristle-like) refers to the cephalic setae, a main feature of the species.
Description. Body cylindrical over most of its length, tapering on tail end, 716–902 μm long. Cuticle with regular transverse rows of small punctations from the level of buccal cavity to tail end, lateral differentiations absent ( Figs 1A View FIGURE 1 , 2B View FIGURE 2 ). Somatic setae and cuticular pores not seen. Lip region more or less rounded, confluent with body. Outer and inner labial sensilla papilliform ( Figs 1A View FIGURE 1 , 2A View FIGURE 2 ). Four cephalic sensilla setiform, about 2 µm long. Spiral amphideal fovea in four turns, located close to anterior end of body ( Fig. 1A View FIGURE 1 ). Buccal cavity about 20 µm long, with a large and heavily cuticularized dorsal tooth; composed of a spacious anterior cyathiform chamber with 12 rugae (ribs) and an elongate posterior chamber with cuticularized walls. Pharynx asymmetrical and muscular, 130–140 µm long, posterior portion with a distinct bulb and a hollow muscle cavity ( Figs 1A View FIGURE 1 , 2A View FIGURE 2 ). Cardia small, broadly conoid. Ventral gland sac-like, just behind the base of pharynx. Tail curved ventrally, 55-66 µm long, conoid with rounded end. Caudal glands and spinneret well developed.
Male. Reproductive system diorchic, with two opposed, outstretched testes. Anterior and posterior testes on the left and right sides of intestine, respectively. Spicules curved, slightly S-shaped, about 28 µm long, gubernaculum knife-like, without dorsal apophysis ( Figs 1B View FIGURE 1 , 2C, D View FIGURE 2 ). One small seta and 11 cup-shaped supplements situated in front of cloaca. Precloacal supplements extending for 27 µm to 225 µm from cloaca towards anterior end, spacing of supplements slightly increased anteriorly ( Figs 1D View FIGURE 1 , 2D View FIGURE 2 ).
Females. Reproductive system didelphic, two ovaries opposed, reflexed ( Figs. 1E View FIGURE 1 , 3B View FIGURE 3 ). Anterior ovary on the right side of intestine, and posterior one on the left side. Vulva in posterior body portion near mid-body. Lips of vulva slightly protruded. Vagina cuticularized, about 0.3 times vulval body diameters long. Uterus spacious. Spermathecae not observed.
Juvenile. Similar to male and females in most morphological characters except for smaller morphological measurements.
Differential diagnosis and discussion. The genus Gomphionema contains only four species ( Gagarin & Thanh, 2009; Bezerra et al., 2018), among which Gomphionema compactum Gerlach, 1957 was described from a juvenile and thus is not recognized as valid. Gomphionema setiforme sp. nov. is most similar to G. parvum Gagarin & Thanh, 2009 , in particular in the absence of lateral differentiation of cuticle and cuticular pores. However, the new species differs distinctly from the latter by its setiform cephalic sensilla (vs. papilliform), S-shaped spicules (vs slightly arched) and the lower number of precloacal supplements (11 vs. 18–21). Both Gomphionema fellator Wieser & Hopper, 1966 and G. typicum Wieser & Hopper, 1966 have lateral differentiation and cuticle pores (vs. present) and have longer spicules (36–38 µm and 41 µm, respectively vs. 28 µm) and more precloacal supplements (15 and 22, respectively vs. 11).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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