Fimoscolex dorivali Dudas, James, Brown & Bartz, 2025

Dudas, Rafaela Tavares, James, Samuel Wooster, Bartz, Marie L. C. & Brown, George Gardner, 2025, New earthworm species of Glossoscolex Leuckart, 1835 and Fimoscolex Michaelsen, 1900 (Clitellata: Glossoscolecidae) from southeastern Brazil, Zootaxa 5589 (1), pp. 321-345 : 329-331

Fimoscolex dorivali Dudas, James, Brown & Bartz sp. nov.

( Figure 7 )

Holotype. Brazil, one adult, São José do Barreiro, São Paulo, Serra da Bocaina National Park , secondary forest along small trail near park entrance gate, in the soil; latitude, longitude: 22°44”7.5’S, 44°36”57.42’W, elevation: 1,499 m asl; February 2009; D. Baretta, J.M. Pereira coll. Sample ID: COFM BRSP0931 .

Paratype. Brazil, one adult, same information as holotype. Sample ID: MZUSP 6444 (former COFMBRSP0932) .

Other material. Brazil, one adult and one juvenile, same information as holotype. Sample ID: COFM BRSP0933 .

Etymology. The species is named for Dorival Grisotto, retired staff member at the Escola Superior de Agricultura Luis de Queiroz (ESALQ) of the University of São Paulo, for his long-term support to earthworm research (over 30 years) at the university, including countless field trips to collect specimens for the work of graduate and undergraduate students.

External morphology. Holotype: body length 65 mm, body mass 0.4 g after ethanol fixation. Diameter pre clitellar (X) 3 mm, in the clitellum ( XVI) 3.5 mm and in post clitellar region ( XXX) 2.9 mm. Number of segments 224. Paratype: length 55 mm, body mass 0.3 g. Diameter at X 3.4 mm, at XVI 3.9 mm and at XXX 3.5 mm. Number of segments 111. Body shape cylindrical. Body pigmentation absent. Prostomium proepilobic, tucked under peristomium. Setae very small beginning in XXIII. Setal arrangement aa:ab:bc: cd = 18:1:5.3:1. Clitellum in XII –XXIII, annular, but in XI to XVI thick and white ( Figure 7A ), while in XVII –XXIII darker color over larger area. Genital markings absent. One male pore on a long conical porophore slit in XVII ( Figure 7A ). Female pore on small bumps medial to ab setae in XIV. Nephridial pores above B.

Internal anatomy. Septa 5/6 very thin, on the anterior quarter of gizzard, 6/7–10/11 thick and 11/12–16/17 membranous but solid ( Figure 7B ). Gizzard in VI, with an average size (width x length) of 1.2 x 0.7 mm. Calciferous glands one pair in XII, of tubular composite structure, with dorsal esophagus wall connection, via gland to esophagus wall. Esophagus-intestine transition origin in XV. Typhlosole originates in XV, simple form till XX, then becomes a cupped fold, until proximally XL. Hearts in X–XI lateral-esophageous. One pair of large nephridia, that have two or three full loops post septa, starting from nephrostome then becoming a large vesicle attached complete to the septum, leading out to nephropore. In XII–XIV very large, white nephridia but no obvious sperm ( Figure 7C ). Testes in XI–XII, inside a large single ventral sac, pushes under hearts in XI, with seminal vesicles as narrow tube expanding from XII to XLV dorsally ( Figure 7B ). The vasa deferentia originate from the anterior part of the testes sac, and then go in an loop form, towards the copulatory bulb. Spermathecae absent. One copulatory bulb, flat disk shape, mid ventral over XVI–XVIII.

Remarks. F. dorivali sp. nov., like F. feijooi sp. nov. described here share a pair of testes sacs. Other species of Fimoscolex , like F. angai , F. bartzi , F. sporadochaetus , F. tairim and F. thayeri also have paired testes sacs, but the new species have larger testes, which occupy segments XI and XII, whereas in all the other species, except F. sporadochaetus the pair is united ventrally on segment XI. However, the setal arrangement of F. sporadochaetus is different than that of F. dorivali sp. nov. and F. feijooi sp. nov., which are both closely paired. Furthermore, the seminal vesicles in F. dorivali sp. nov. are a mass of zig-zagging tubes, whereas in F. feijooi sp. nov. they are aligned paired tubular strips.

Figures

FIGURE 7. Fimoscolex dorivali sp. nov. Holotype. A. External lateral view showing the clitellum (Cl) and male pore (MP) in the middle of segment XVII. B. Internal general view with emphasis on the thick septa (Sp) and long seminal vesicles (SV). C. Nephridia with slightly iridescence.