Fimoscolex pereirai 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 : 328-329

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

( Figure 6 )

Holotype. Brazil, one adult, Rio de Janeiro, Itatiaia , old growth forest, in the soil; latitude, longitude: 22°26”43.8’S, 44°36”37.18’W, elevation: 927 m asl; 11 February 2009; D. Baretta, J.M. Pereira coll. Sample ID: COFM BRRJ0059 .

Paratype. Brazil, one adult, same information as holotype. Sample ID: MZUSP 6446 (former COFM BRRJ0060 ) .

Other materials. Brazil, two adults, same information as holotype. Sample ID: COFM BRRJ0055 .

Etymology. The species is named in honor of Jamil de Morais Pereira, for his support over the years to soil macrofauna and earthworm research, collecting many specimens including several new earthworm species from the Atlantic Forest.

External morphology. Holotype: body length 75 mm, body mass 0.09 g after ethanol fixation. Diameter on pre clitellar region (X) 2 mm, at the clitellum ( XVI) 1.8 mm and in the post-clitellar region ( XXX) 1.5 mm. Number of segments 268. Paratype: length 39 mm, body mass 0.08 g after fixation. Diameter at segment X 1.6 mm, at XVI 2 mm and at XXX 2 mm. Number of segments 137. Body shape cylindrical. Body pigmentation absent. Prostomium prolobic. Setal arrangement at XXX-L, aa:ab:bc:cd: = 5.6:1.7:1:1.2. Clitellum in XVI – XXII, 1/2XXIII, annular ( Figure 6B ). Genital markings are absent. One male pore on XVII, on a rounded swelling ( Figure 6A ). Female pore mid in XIV, in line with the nephridiopores. Nephridial pores in B line.

Internal anatomy. Septa 6/7–10/11 thick, 5/6 thin, over the gizzard, 11/12 more membranous. Septa 14/15 make a blanket over the intestine, dorsal to lateral of intestine. Gizzard in VI, with an average size (width x length) of 0.8 x 0.6 mm. Calciferous glands one pair in XII, dorsal, joined at anterior ends. Esophagus-intestine transition origin in XV. Typhlosole origin in XV, all laminar, simple except three or four cups in XIX–XXI area. One pair of lateroesophageal hearts in XX–XI, almost connected to calciferous glands by lateral vessels in XII–IX. One pair of nephridial stripes per segment, vesiculated exonephric in XIII–XVI. Presence of iridescent nephridia, under the septal blanket, and then going over the dorsal-lateral portion of the intestine. These nephridia are in the form of stripes and are present in each segment. Paired testes sacs in XI, fused ventrally and connected to seminal vesicles by fine dorsal tubes ( Figure 6C ). Seminal vesicles right side XIII narrow, widening after XX, folded in XX–XXVIII. Left side also narrow ventral to segment L. Spermathecae absent. One copulatory bulb, large and lenticular, mid ventral in XVI–XVIII over half AB lines.

Remarks. F. pereirai sp. nov. is similar to F. barettai sp. nov. and F. dorivali sp. nov. in the shape and extent of the clitellum (annular, XVI–XXII), except that in the latter species it extends to ½ XXIII. However, these species differ in that F. barettai sp. nov. has unpaired testes sac in XI, while F. dorivali sp. nov. has paired sacs in XI and XII and F. pereirai sp. nov. has paired sacs in XI. Furthermore, F. pereirai sp. nov. differs from all other Fimoscolex species in that the calciferous glands are joined at the anterior end in segment XII.

Figures

FIGURE 6. Fimoscolex pereirai sp. nov. Holotype. A. External ventral view showing the male pore (MP) in the middle of the round opening, in segment XVII. B. External lateral view of clitellum. C. General view showing seminal vesicles (SV), testis sac (TS) and calciferous glands (CG).