Pheretima losbanosensis, Aspe & Obusan, 2023

Aspe, Nonillon M. & Obusan, Marie Christine M., 2023, Pheretimoid earthworms (Clitellata: Megascolecidae) cultivated in a vermifacility in Los Baños, Laguna, Philippines, with description of a new species, Zootaxa 5255 (1), pp. 101-112 : 103-104

Pheretima losbanosensis n. sp.

( Figure 1 )

Material examined. Holotype: adult ( PNM 4649 ), Pleasant Village , Los Banos, Laguna (14°09’29.9”N, 121°15’17.4”E), 24 m asl., Luzon Island, Philippines, coll. N. Aspe, M. R. F. Mapile 2 July, 2019 . Paratypes: 3 adults ( PNM 4650 ) ; 2 adults (UPLBMNHLS (EW) 158), same collection data as for holotype .

Etymology. The species is named after Los Baños City in Laguna Province, the type locality.

Diagnosis. Large brown worms with adult size of 220–228 mm x 8–9 mm; equators pigmented; three pairs of spermathecal pores at 6/7–8/9; distance between spermathecal pores and between male pores 0.18 and 0.15 circumference apart ventrally, respectively; setae on vii and xx 26–36 and 56–66, respectively. Spermathecae paired in vii, viii, and ix, with nephridia on ducts; each spermatheca small with ovate ampulla, stout muscular duct, stalked diverticulum attached to duct near ampulla, terminating in ovate receptacles, stalks long and thin, some with convolutions; prostates small in xvii to xix; penis present.

Description. In live animals, dorsal brown, ventral pale, equators pigmented; Length 220–228 mm (n= 6 adults); diameter 8–9 mm at x, 8 mm at xx; body cylindrical in cross-section, tail blunt; 117–128 segments. First dorsal pore at 12/13; spermathecal pores three pairs at 6/7–8/9, inconspicuous, distance between spermathecal pores 5 mm (0.18–0.20 circumference apart ventrally). Female pore single in xiv. Openings of copulatory bursae paired in xviii, distance between openings 3.5–4 mm (0.15–0.16 circumference apart ventrally), 4–6 setae between openings. Clitellum annular, from xiv to xvi. Setae evenly distributed around segmental equators; 26–36 setae on vii, 56–66 setae on xx, dorsal setal gaps present, ventral setal gaps lacking. Genital marking lacking.

Septa 5/6–8/9 and 10/11–13/14 thin, 9/10 lacking. Dense tufts of nephridia on anterior faces of 5/6 and 6/7; nephridia of intestinal segments located mainly on body near septum/body wall junction. Large gizzard extending from ix to x, esophagus with low vertical lamellae x–xiii. Intestinal origin xv, caeca simple originating in xxvii, extending forward to xxiii; Hearts in x to xiii, esophageal; commissural vessels in vi, vii, and ix, lateral; those in viii extend to gizzard; supra-esophageal vessel extends from x to xiii; extra-esophageal vessel joins ventral esophageal wall in xi, receives efferent parieto-esophageal vessel in xiii.

Ovaries and funnels free in xiii. Spermathecae paired in vii, viii, and ix, with nephridia on ducts; each spermatheca small with ovate ampulla, stout muscular duct, stalked diverticulum attached to duct near ampulla, terminating in ovate receptacles, stalks long and thin, some spermathecae with convoluted stalks. Male sexual system holandric, testes and funnels enclosed in paired sacs in x, xi; seminal vesicles xi, xii, each with digitate dorsal lobe; vesicles of xi enclosed in testes sac; vas deferens slender, free from body wall to ental end of prostatic ducts; prostates small in xvii to xix, each a single, dense, racemose mass; short muscular duct entering center of copulatory bursa; paired small copulatory bursae xviii; secretory diverticula lacking; tapering penis present.

Remarks. Pheretima losbanosensis n. sp. belongs to P. dubia group in Sims & Easton (1972), characterized by having three pairs of spermathecal pores in 6/7–8/9. Including the new species, P. dubia group is now composed of 12 species: P. philippina Rosa, 1981 from Cebu and Mindoro; P. callosa Gates, 1937 from Benguet Province; P. balbalanensis Hong & James, 2010 ; P. banaoi Hong & James, 2010 from Kalinga Province; P. lamaganensis Hong & James, 2011a ; P. julkai Hong & James, 2011a from Mountain Province; P. globosa Hong & James, 2011b in Kalbaryo, Pagudpud, Ilocos Norte; P. vungtauensis Nguyen et al. 2018 from Vietnam; and P. dubia Horst, 1893 ; P. korinchiana Cognetti, 1922 ; and P. poiana Michaelsen, 1913 from Indonesia ( Table 1 ). Among the members of P. dubia group, the new species is most similar to P. philippina in length (180–240 mm). However, the latter has slate gray pigmentation (vs. brown in P. losbanosensis n. sp.), has more setae in vii and xx (44 and>70, respectively vs. 26–36 and 55–60 in P. losbanosensis n. sp.), has its first dorsal pore in 11/12 (vs. 12/ 13 in P. losbanosensis n. sp.), and has no dorsal setal gaps. The caeca in P. philippina extends from xxvi to xxiii and its prostate gland is confined only in xviii while the caeca in P. losbanosensis n. sp. extends from xxvii to xxiii and its prostate gland extends from xvii to xix. Also, the spermathecal ampulla of P. philippina is pear-shaped, the stalked diverticulum terminating in small, round receptacle, and the stalk is shorter than the ampulla. On the other hand, the spermathecal ampulla and the receptacle of the new species are ovate, and the stalk is longer than the ampulla. Pheretima poiana (290 mm) and P. callosa (330 mm) are larger than the new species (220–228 mm) while P. korinchiana (83–180 mm), P. dubia (80–140 mm), P. vungtauensis (132–169), P. julkai (49–69 mm), P. banaoi (53–60 mm), P. lamaganensis (46–55 mm), P. balbalanensis (42–50 mm) and P. globosa (35–42 mm) are significantly smaller. Pheretima losbanosensis n. sp. has ovate spermathecal diverticulum and short prostatic duct while P. poiana has sausage-shaped spermathecal diverticulum and the prostatic duct is in an S-curve. Pheretima poiana also has distinctively long tubular dorsal lobes of the seminal vesicles, which are absent in P. losbanosensis n. sp. The distances between spermathecal pores and between male pores are wider in P. poiana (0.4 and 0.29, respectively), P. vungtauensis (0.4 and 0.35, respectively), P. korinchiana (0.19–0.22 and 0.19–0.23, respectively), P. dubia (0.38 and 0.17, respectively), P. lamaganensis (0.27–0.28 and 0.21–0.22, respectively), P. julkai (0.20–0.23 and 0.18–0.20, respectively), P. balbalanensis (0.28–0.32 and 0.22, respectively), P. banaoi (0.19–0.22 distance between male pores only), and P. globosa (0.32 and 0.22, respectively) compared with the new species (0.18 and 0.15, respectively). There are more setae on vi and xx in P. callosa (71 and 114, respectively) and more setae on vii in P. lamaganensis (43–44) while there are fewer setae on xx in P. balbalanensis (41–42) and in P. banaoi (46–47) compared with the new species (26–36 and 55–66, respectively).Also, there are more setae between male pores in P. korinchiara (12), P. vungtauensis (11–17), P. dubia (10), P. lamaganensis (7–10), P. julkai (6–10), P. balbalanensis (6–8), P. banaoi (6–12) and P. globosa (9). In addition, the new species differs from the other species in the relative length of caeca (xxvii–xxiii in P. losbanosensis n. sp. vs. xxvii–xxv in P. julkai and P. lamagensis , xxvii–xxiv in P. banaoi and P. balbalanensis , and xxvii– xxvi in P. globosa ) and size of prostate glands (xvii–xix in P. losbanosensis n. sp. vs. xvi–xviii in P. vungtauensis and P. banaoi and xxvii-xxviii in P. julkai , P. banaoi , P. lamagensis , P. balbalanensis and P. globosa ).

Figures

FIGURE 1. Pheretima losbanosensis n. sp. (A) Male pores area. (B) Spermatheca. (C) Prostate gland. Scale bar: 1mm.