Amynthas carnosus subsp. naribunji Blakemore 2013
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 naribunji blakemore, 2013

description: Amynthas carnosus naribunji Blakemore, 2013
Amynthas pingi: Blakemore 2013 a: 60, figs 4, 5.
Material examined.
Specimen IDs: 551 R 3 (01–10), 10 adults from Longwan Park, Huludao Pref., Liaoning Prov. One specimen from Beijing is a juvenile and was poorly preserved. Thus, its morphological examination was not performed. However, the molecular data is presented (DNA ID: BJCY _ 42, Fig. 1).
Diagnosis.
Spermathecal pores four pairs in 5 / 6 / 7 / 8 / 9, located latero-ventrally (0.29–0.30 mm), each with pre-intersegmental hemispherical arc (spermathecal papillae) anterior to intersegments (Fig. 6). Pre-clitellar genital markings absent (complying with Kobayashi Type I in Blakemore 2013 a); if present, one to three pairs; pre-setal in VIII and IX when one or two pairs and having a post-setal pair in VIII when three pairs (complying with Kobayashi’s Types III, IV, and VIII); asymmetrical patterns also present (Fig. 7). Male pores superficial in XVIII having “ disc-like ” genital markings paired posterio-median to male pores (Fig. 8).
Description.
Length 185–228 mm. Color of preserved specimens may have varying shades of brown but dorsum generally dark brown in pre-clitellar region to brown in post-clitellar region, fading to lighter brown towards posterior end with darker clitellum, while ventrum part is paler / fleshy color. Clitellum width 5.8–8.3 mm. Segments 115–137. Prostomium epilobous. First dorsal pore on 12 / 13. Clitellum annular at XIV – XVI without setae or dorsal pores. Setal arrangement perichaetine, setae between male pore 18–19. Female pore single and circular, midventral at XIV.
Spermathecal pores large, having four pairs in 5 / 6 / 7 / 8 / 9 and widely-spaced, latero-ventral (0.29–0.30 mm) in pre-intersegmental hemispherical arc (spermathecal papillae). Pre-clitellar genital markings circular in shape, latero-ventral (0.25–0.29 mm), randomly located in pairs (three pairs / two pairs / one pair, a total of 2–6 genital markings), or asymmetrically located on one side (1–2 genital markings), about 0.38–0.59 mm in diameter.
Male pores superficially paired in XVIII close to lateral margin (with ventral distance 0.26–0.29 mm) on large circular porophores. Post-clitellar genital markings distinguishably paired, post-setally in XVIII, mid-ventral to male pore, 0.42–0.69 mm in diameter.
Septa 4 / 5–7 / 8 and 10 / 11–14 / 15 thickened, 8 / 9 / 10 absent. Esophageal gizzard within VIII-X. Intestinal origin at XV (or XIV). Intestinal caeca simple, paired in XXVII, extending anteriorly to XXII. Last hearts in XIII.
Four pairs of spermathecae in VI-IX. Ampulla ovate, wrinkled; ducts short and stout. Diverticula reaching one-third to half of ampulla with a slender stalk and a wider seminal chamber; seminal chamber elongated or botuliform. Accessory glands sessile and round.
Seminal vesicles paired in XI and XII, large, smooth, yellowish, posterior pair larger but not as obvious compared to A. c. carnosus, each with a dorsal lobe. Ovaries present. Prostate glands paired in XVIII, large, lobulated, covering XVI-XX; ducts thick and large, U-shaped. Accessory glands round, sessile, or slightly lobed, corresponding to each genital marking around male pore area.
Distribution.
Northern China (Liaoning, Beijing) and South Korea (Ulleung Island).
Remarks.
There is not much of a thorough morphological description of A. carnosus naribunji in the original account of Blakemore (2013 a) (see Suppl. material 1: table S 3) aside from its single illustration of paired post-clitellar genital markings in the male pore area and a spermathecal pore with corresponding spermathecae shown in fig. 4 by Blakemore (2013 c).
Notable features of A. c. naribunji in comparison with A. c. carnosus were its slightly larger size with lengths of 185–228 mm, typically wide-spaced pre-clitellar genital markings with a maximum number of six (three pairs) to at least three genital markings; pre-setal / post-setal in VIII and pre-setal in IX. In contrast, A. c. carnosus is typically medium to smaller size, with mostly only four genital markings (two pairs) or less, either wide or closely-spaced pre-clitellar (Table 3).
The distinctive character of having “ a pair of genital markings posterio-median to male pores ” in A. c. naribunji may distinguish it from those of A. c. carnosus (Blakemore, 2013 a). However, it is now undeniable that this seemingly “ distinctive character ” was likewise observed in the A. c. carnosus specimens from Liaoning and Henan (Fig. 8). Here, we dismiss the former notion of Blakemore (2013 a) “ to consider for exclusion Kobayashi’s Types I and II markings ” as a distinctive character for the A. c. carnosus subspecies, A. c. naribunji. Although this might be the case, one cannot ignore the certain degree of dissimilarity between the two subspecies’ morphological characters (e. g., the shape of male pore porophore and the distinct shape of the genital markings in A. c. naribunji, described as “ disc-like ” by Blakemore). As such, applications of state-of-the-art methodologies such as high-throughput sequencing or geometric morphometric (Marchán et al. 2020) may be adopted that go beyond traditional methods of taxonomic diagnosis (which in this case is rather insufficient to “ quantify ” the degree of variations). Nevertheless, the incorporation of genetic data such as DNA barcoding and calculating K 2 P intraspecific distances (as conducted in this study) may aid in suggesting subspecies delineation.
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