Amynthas carnosus subsp. carnosus Goto & Hatai 1899
Creators: name: Han, Anne Charis N.
name: Zhang, Yufeng
name: Miao, Pu
name: Wu, Shaolong
name: Xiao, Nengwen
name: Qin, Mingyan
name: Zhao, Huifeng
name: Wu, Donghui
name: Aspe, Nonillon M.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Clitellata
Crassiclitellata
Megascolecidae
Amynthas
Amynthas carnosus
Amynthas carnosus carnosus goto &amp; hatai, 1899

description: Amynthas carnosus carnosus Goto & Hatai, 1899
Perichaeta carnosa Goto & Haitai, 1899: 15.
Pheretima carnosa – Kobayashi 1936: 115.
Amynthas carnosus – Sims and Easton 1972: 235. Blakemore 2012: 36; 2013 a: 58; 2013 c: 101. Carrera-Martínez and Snyder 2016: 297. Chang et al. 2016: 505.
Amynthas pingi (Stephenson, 1925) – Sims and Easton 1972: 235. Blakemore 2013 c: 112.
Material examined.
Specimen IDs: 362 R 1 _ 01, 02, 04, 05, 06, 07, 09, seven matures from Nanshan Park, Jinzhou, Liaoning; 533 R 70 _ 08, 09, 10, three matures from Jinjiang Mt. Park, Dandong, Liaoning; LFXHR 7 _ 02, 04, 05, three matures from Zhuti Park, Xianghe County, Langfang, Hebei; LFSF _ 013, one mature from Langfang Normal University, Anci District Langfang, Hebei; E 29 _ 05, one mature from an anonymous park in Dongli District, Tianjin Municipality; HNLNR 2 _ 04, 05, 06, three matures from the tobacco field in Xiaojie Town, Luoning County, Luoyang, Henan; HNSQ _ 07, 13, 15, three matures under the bushes in Shangqiu Normal University, Liangyuan District, Shangqiu, Henan.
Diagnosis.
Length 105–210 mm. Spermathecal pores having four pairs in 5 / 6 / 7 / 8 / 9, rarely 3 pairs in 6 / 7 / 8 / 9, with pre-intersegmental hemispherical arc (spermathecal papillae). Dorsal pores typically from 12 / 13. Pre-clitellar genital markings typically with two pairs, pre-setal in VIII and IX; these genital markings paired either widely or closely apart (B 1 and B 2, Fig. 3); Post-clitellar genital markings prominent, up to three pairs median to male pores; first pair pre-setal on XVIII, slightly median to male pores; second pair post-setal and more medial than the first; third pair pre-setal in XIX (Fig. 4). Male pores superficially paired in XVIII close to the lateral margin on round or elliptical porophores (Fig. 4). Ampulla ovate to narrowly ovate (Fig. 2 D-F). Intestinal caeca simple at XXVII.
Variations.
For the A. c. carnosus from China, the number of spermathecal pores and spermathecae are variable: 14 out of 16 specimens typically have four pairs in 5 / 6 / 7 / 8 / 9, one specimen has three pairs in 6 / 7 / 8 / 9 (LFXHR 7 _ 05), and another one has five pairs in 4 / 5 / 6 / 7 / 8 / 9 (HNLNR 2 _ 05) (Fig. 2). However, despite these variations, molecular analyses have shown them to belong in the same clade with little genetic divergence within the clade (Table 2, Fig. 1). Two specimens from South Korea and one specimen from the USA have three pairs of spermathecal pores in 6 / 7 / 8 / 9 (Kobayashi 1936; Carrera-Martínez and Snyder 2016). However, prior to this study, no other specimen with five pairs was recorded elsewhere.
Distribution.
China (Liaoning, Beijing, Tianjin, Hebei, Henan, and Shanghai), Japan (Kyushu, Honshu, and Hokkaido), and South Korea (Incheon, Jeju Island).
Remarks.
Detailed descriptions of A. carnosus were reported by Kobayashi (1936), Ohfuchi (1937), and Blakemore (2012, 2013 a, c). Rather than typical closely spaced mid-ventral pre-clitellar genital markings (Blakemore 2012), widely spaced ones are mostly observed with the A. carnosus specimen from China, which resembles those Hikone specimens from Japan (Tokyo An- 460 - DNA JET- 112) [cf. fig. 3 by Blakemore (2013 a)]. In contrast, the closely spaced pre-clitellar genital markings of the Liaoning specimens (Dandong, DNA 533 R) match those of the South Korean specimen from Geoman (NIBR IV 261234 - DNA w 37) and the Japanese neotype of A. carnosus (Tokyo An 435) [cf. fig. 2 by Blakemore (2013 a)].
A comparison of characters from the specimens of China, Japan (a neotype NSMT An 435 from the Tokyo Museum) (Blakemore 2012), and the USA (Kansas) (Chang et al. 2016) is presented in Suppl. material 1: table S 2. External characters such as the number of spermathecal pores and segment locations of pre-clitellar genital markings match among specimens from different countries. However, internal character variations are observed in the position of the intestinal caeca, which was reported to begin at XXVII and extend to XXIII or XXIV (Blakemore, 2012; 2013 b; 2013 c; Chang et al. 2016), while the intestinal caeca in the Chinese specimens extends up to XX, XXI (or XXIII) (Fig. 5), 2–3 segments more anterior than those from the two previous accounts. Moreover, some character measurements that were not presented in the other two accounts, such as the ventral distances between male pores (0.25–0.29 mm), spermathecal pores (0.28–0.30 mm), and genital markings (latero-ventrally with 0.21–0.29 mm distance apart or mid-ventrally with 0.08 mm distance apart), were added to further aid species identification.
Kobayashi (1936), in his thorough investigation of A. carnosus, presented “ permissible ” variations on the pre-clitellar and post-clitellar genital markings [text-figs. 1–2 in Kobayashi (1936)]. The pre-clitellar genital making variations in the A. c. carnosus from China comply with Kobayashi’s Types IIII, VI, and VIII (see Fig. 3), while the post-clitellar genital marking variations comply with Kobayashi’s Types II, IV, and V (see Fig. 4). It is important to take note that genital marking patterns can also be considered a distinctive character for species identification (e. g., Nguyen et al. 2020; Aspe et al. 2021).
description: Published as part of Han, Anne Charis N., Zhang, Yufeng, Miao, Pu, Wu, Shaolong, Xiao, Nengwen, Qin, Mingyan, Zhao, Huifeng, Wu, Donghui & Aspe, Nonillon M., 2024, Distribution and systematics of the cosmopolitan Amynthas carnosus complex (Crassiclitellata, Megascolecidae) from eastern Asia, pp. 1061-1073 in Zoosystematics and Evolution 100 (3) on pages 1061-1073, DOI: 10.3897/zse.100.119292