Amynthas jioupengensis Shen, 2025

Amynthas jioupengensis Shen sp. nov.

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Fig. 4 View Fig

Amynthas corticis View in CoL – James et al. 2005: 1023 (partim).

Diagnosis

Length 40 mm. Segments numbering 85. Setae 38 in VII, 44 in XX, 12 between male pores. First dorsal pore in 12/13. Clitellum XIV–XVI. Spermathecal pores invisible. Male pores 0.34 body circumference ventrally apart in XVIII, each with an anterolateral genital papilla. Genital papillae small, widely paired in presetal VII–VIII, and 7 or 8 in a row, closely along setal lines in presetal XVIII–XIX. Spermathecae four pairs in VI–IX. Seminal vesicles two pairs in XI and XII. Prostate glands paired in XVI–XIX. Prostatic ducts small, C-shaped in XVIII. Accessory glands stalked.

Etymology

The species is named after its locality, Jioupeng, Pingtung County, Taiwan.

Type material

Holotype

TAIWAN • clitellate (mature) specimen; Jioupeng , Pingtung County; 22°06′18″ N, 120°50′56″ E; 149 m a.s.l.; 29 Apr. 1999; Hsi-Te Shih leg.; NMNS 4054-033 View Materials . GoogleMaps

Description

Length (mature) 40 mm. Number of segments 85. Setae regularly distributed around segmental equators, size and distance regular, numbering 38 in VII, 44 in XX, 12 between male pores in XVIII. Prostomium epilobous. First dorsal pore in 12/13. Clitellum XIV–XVI, smooth, setae and dorsal pores absent, length 1.8 mm and width 3.0 mm. Spermathecal pores invisible. Genital papillae small, widely paired in presetal VII–VIII ( Fig. 4A View Fig ), each papilla about 0.1 mm in diameter. Female pore single, mid-ventral in XIV.

Male pores paired, ventro-lateral in XVIII, paired pores 0.34 body circumference ventrally apart, each pore with an anterolateral genital papilla. In addition, genital papillae 7 or 8 in a row, closely along setal lines in presetal XVIII–XIX ( Fig. 4B View Fig ). Each papilla small, about 0.1 mm in diameter. Preserved specimens brown in color.

Septa 5/6–7/8 thick, 8/9/10 absent, 10/11–13/14 thick. Nephridial tufts on anterior faces of 5/6/7. Gizzard in VIII–X. Intestine enlarged from XV. Intestinal caeca paired in XXVII, simple, surface slightly wrinkled, extending anteriorly to XXV. Esophageal hearts paired in XI–XIII.

Spermathecae four pairs in VI–IX. Ampulla elongated oval-shaped, 0.6–0.9 mm in length and 0.4–0.5 mm in width, with a short, slender stalk about 0.3 mm long. Diverticulum with a round, iridescent seminal chamber about 0.1 mm in length and a short, slender stalk 0.3–0.4 mm in length ( Fig. 4C View Fig ). Accessory glands stalked, about 0.2 mm in total length, each corresponding to external genital papilla. Ovaries paired in XIII.

Holandric. Testes oval, two pairs in ventrally joined sacs in X and XI, first pair large. Seminal vesicles two pairs in XI and XII, each with a round dorsal lobe. Prostate glands paired in XVI–XIX, leafy, follicular. Prostatic ducts small, C-shaped in XVIII ( Fig. 4D View Fig ). Accessory glands stalked.

Distribution

Known only from type locality (Jioupeng, Pingtung County, Taiwan).

Remarks

The character of the rows of genital papillae along the setal lines in presetal XVIII–XIX in A. jioupengensis sp. nov. easily separates it from A. corticis . The papilla arrangement in A. jioupengensis sp. nov. bears a resemblance to that in A. evansi . However, A. evansi is much larger (body length 120 mm and segments numbering 120 for an aclitellate specimen) and has a coiled diverticular stalk ( Beddard 1900; Stephenson 1932). Amynthas libratus Tsai & Shen, 2010 from eastern Taiwan also has four pairs of spermathecae in VI–IX and papillae in horizontal rows closely along the setal lines, but the positions of these papillae are in VII–IX, XVII, XIX, and additionally along the intersegmental furrows of 17/18 and 18/19 ( Tsai et al. 2010). Besides, A. libratus has an anteriorly placed first dorsal pore in 5/6 ( Tsai et al. 2010).