Amynthas corticis ( Kinberg, 1867 )

Chang, Chih-Han, Snyder, Bruce A. & Szlavecz, Katalin, 2016, Asian pheretimoid earthworms in North America north of Mexico: An illustrated key to the genera Amynthas, Metaphire, Pithemera, and Polypheretima (Clitellata: Megascolecidae), Zootaxa 4179 (3), pp. 495-529 : 506

3. Amynthas corticis ( Kinberg, 1867)

( Figures 1 B, 9)

Perichaeta corticis Kinberg, 1867: 102 .

Pheretima diffringens (Baird, 1869) — Gates 1937: 350; 1954: 227; 1958: 31; 1963: 12; 1982: 44.

Amynthas corticus — Sims & Easton 1972: 235. Easton 1981: 49.

Amynthas diffringens — Sims & Easton 1972: 235. Reynolds 1978: 120, 127; 2010: 144; 2011: 270. Reynolds & Wetzel 2004: 88; 2008: 179.

Data sources. Gates (1937, 1972, 1982); Blakemore (2013a).

Diagnosis. Size 45–170 mm by 3–6 mm. Segment numbers 79–121. Color of live specimens greenish brown. Male pores paired in XVIII, simple, on circular to oval porophores. Post-clitellar genital markings present or absent, when present, 1–3, small, around each male porophore, confined within concentric circular folds. Spermathecal pores four pairs in 5/6/7/8/9. Pre-clitellar genital markings variously present, pre-setal and post-setal; the pre-setal ones widely paired or unpaired on VII–X, behind and median to spermathecal pores; the post-setal ones just in front of each spermathecal pore. Female pore single in XIV. First dorsal pore 10/11, 11/12, or 12/13. Spermathecae four pairs in VI–IX, duct shorter than ampulla, diverticulum with an oval seminar chamber and a longer, slender stalk; stalked glands associated with external genital markings. Prostate glands absent, present, or rudimentary, ducts usually present. Intestinal caeca paired in XXVII, simple, extending anteriorly to XXII.

Remarks. Historically referred to as Pheretima diffringens or Amynthas diffringens , A. corticis has been frequently reported in the US. The name A. diffringens has been regarded as a junior synonym of A. corticis for a long time ( Easton 1981; Blakemore 2003; 2010a; Chang et al. 2009a); recent resurrection of A. diffringens by Blakemore (2013c) based on morphology of syntype specimens is still pending confirmation or rejection by molecular studies. The first record of A. corticis in the continental US was in 1866 in San Francisco, California, although the specimen was originally misidentified as part of “ Pheretima californica ” ( Gates 1937, 1954, 1982). Reproduction of A. corticis is usually parthenogenetic. Amynthas corticis , an epi-endogeic species, competes directly with native millipedes for food resources in the southern Appalachian Mountains (Snyder et al. 2009).

Figures

FIGURE 1. Color photographs of live individuals of (A) Amynthas agrestis, (B) Amynthas corticis, (C) Amynthas gracilis, (D) Amynthas hupeiensis, (E) Amynthas minimus, (F) Amynthas morrisi, (G) Amynthas tokioensis, (H) Metaphire californica, (I) Metaphire hilgendorfi, (J) Metaphire posthuma, (K) Pithemera bicincta, and (L) Polypheretima elongata, showing interspecific variations in colorations and body shapes. Specimens are from US (A, B, D, G, I) and Taiwan (C, E, F, H, J, K, L). Photo credit: Chih-Han Chang (A, B, D, E, G, H, I) and Wen-Jay Chih (C, F, J, K, L). The photographs of A. minimus and M. californica have been previously presented in Chang et al. (2009 a).