Fimoscolex sp.

Dudas, Rafaela Tavares, Bartz, Marie Luise Carolina, Cunha, Luis & Brown, George Gardner, 2025, New species of Glossoscolex and Fimoscolex earthworms (Oligochaeta: Glossoscolecidae) from the Brazilian Atlantic Forest and Cerrado biomes, Zootaxa 5728 (1), pp. 79-106 : 97-98

Fimoscolex sp. 51 Dudas, Brown & Bartz

( Figure 17 )

Material. COFM BRPR2149 , one adult , annual crops under no-tillage system, in 0–20 cm soil, by TSBF method, Mangueirinha , Paraná, Brazil, -26.050852, -52.237767, 981 m asl, August 08, 2023, G.G. Brown, G.C. Francisco, M.L.C. Bartz, N. Durães , R. T. Dudas , R. Roani , T. Ferreira, W.C. Demetrio colls .

COFM BRPR2151 , one adult amputee, annual crops under no-tillage system, in 0–20 cm soil, by TSBF method, Mangueirinha , Paraná, Brazil, -26.051079, -52.237655, 981 m asl, August 08, 2023, G.G. Brown, G.C. Francisco, M.L.C. Bartz, N. Durães , R. T. Dudas , R. Roani , T. Ferreira, W.C. Demetrio colls .

External morphology diagnosis. Body length 33 in one individual and 39 mm in the other, after ethanol fixation. Number of segments: 97 in one individual and 164 in the other. Diameter: 1.3 mm in one individual and 1.4 mm in the other, in the pre clitellar region (segment X). Body cylindrical, non-pigmented after fixation. Prostomium epilobic. Setae closely paired; setae ab visible from IV onwards. Setal arrangement aa:ab:bc:cd:dd, 17.7:1:2.5:1.1:17.2 at segment XXX. Clitellum in XV–XXII saddle shaped. Genital marks or tubercula pubertatis absent. Female pore not seen. One male pore in the middle of the segment XVII on a conical protuberance. Nephropores near B line.

Internal morphology diagnosis. Septa strong and membranous in 7/8/9. Gizzard in VI. One pair of calciferous glands in XII of composite tubular structure. Holonephridial, exonephric, stomate, positioned close to the body wall and intestine, non-vesiculated, whitish, and slightly recurved, free in the coelom. Intestine begining in XV, with typhlosole commencing in the same segment. Five pairs of hearts, with last pair in XI. Paired testes sacs in XI under the end of the calciferous glands. Seminal vesicles in XII to XV, ventrally in two thin strips. Ovaries not seen. Spermathecae absent. Single oval copulatory bulb in XVII.

Remarks. Fimoscolex sp. 51 exhibits morphological features similar to F. bartzi Bartz & James, 2012 , however, due to the absence of an ovisac, the geographical distance between the species, and the lack of DNA sequences from both species, we consider this as a separate Fimoscolex species for the meantime. Fimoscolex sp. 51 has similar clitellum location (XV–XXI) to F. angai Righi, 1971 , F. inurus Cognetti, 1913 , and F. tairim Righi, 1974 , although the latter has an annular shape instead of a saddle. The difference between Fimoscolex sp. 51 and F. angai is the position of the seminal vesicles (XII–XV in the former species), while in F. angai , they are long strips in XII–XIX, XXI. For F. inurus , the position of the sacs was not provided in the description, however the copulatory bulbs of F. inurus are in XVI–XVIII, while in Fimoscolex sp. 51 the bulb occupies only XVII.

The species name follows a sequential order of potentially new species deposited in the Fritz Muller Oligochaete Collection (COFM). The formal description of this species is awaiting availability of molecular data from Fimoscolex bartzi for comparative purposes.

Figures

FIGURE 17. Fimoscolex sp.51. Holotype. A. External lateral view of the clitellum (Cl) and the single male pore (MP). B. External ventral view with emphasis in the male pore. C. Internal view showing the copulatory bulb (CB).