Martiodrilus (Maipure) tapiai, Feijoo & Lavelle, 2023

Feijoo, Alexander & Lavelle, Patrick, 2023, New species and records of earthworms (Annelida, Oligochaeta: Crassiclitellata) in small holder farming systems in the Peruvian Amazon, Zootaxa 5255 (1), pp. 157-170 : 163

Martiodrilus (Maipure) tapiai sp. nov.

( Fig. 3A–D )

Etymology. The name of the species was given as a tribute to Dra. Sandra Tapia Coral, Professor of Research National Learning Service (= acronym in Spanish SENA), Leticia, Colombia, for all her important contributions to the knowledge on tropical earthworms and their ecology, especially in the Amazon region.

Holotype. Clitellate specimen (CNLT-UTP-0358). Locality: Perú, Department of Loreto, Santa Rosa Farm (5°53'56'' S, 76°10'34'' O). Type of vegetation: Forest fallow Altitude : 168 m. a.s.l. Sampling depth: 20 cm. Collection dates: 16 October 2016. Collectors: Obed Carrascal Torres.

Paratypes. Four adults, five juveniles (CNLT-UTP-0359).Same collection data as holotype .

Description. Epigeic species, with a light blue to Bermuda grey-colored dorsum, milky-white ventrum, and cylindrical body. Holotype: length (preserved) 132 mm, diameter 3.8 mm in preclitellar region (segment 8), 4.7 mm at clitellum, and 3.4 mm in mid-posterior region. Number of segments: 186. Paratypes (four adults): Adult 1: 122 mm long, diameter 2.7 mm in preclitellar region, 3.3 mm at clitellum, 3.3 mm in mid-posterior region, number of segments: 112. Adult 2: 88.7 mm long, diameter 2.8 mm in preclitellar region, 3.2 mm at clitellum, 2.8 mm in mid-posterior region; number of segments: 119. Adult 3: 110 mm long, diameter 3.0 mm in preclitellar region, 3.6 mm at clitellum, 3.4 mm in mid-posterior region; number of segments: 170. Adult 4: fragmented. The first segment invaginated. The prostomium short and lobe-shaped. Eight rows of closely paired setae are visible (a, b, c, d) as of segment 4. Common setae measures 0.3 mm, has a slightly concave shape and then presents a strong curvature to finish with a hook shape ( Fig. 3A ). Distance between setae in mid-body region (segments 40–50); aa:ab:bc:cd:dd = 5.2:1:0.6:0.3:17.4. Genital setae in segments 14, 15, 16, 17, 18, 19 measure 0.7 mm, the genital setae are elongated with a slight curvature in the proximal third with semilunar marks and then ends in a spear-shaped point ( Fig. 3B ). Clitellum blue in the dorsal region and milky white ventral (preserved), saddle-shaped, in segments 14–25 (=12 segments); tubercula pubertatis between segments 19–24 ( Fig. 3C ). Male pores in segment 18/19, female pores in segment 14/15. Nephropores aligned with setae c. Four pairs of spermathecal pores observed in intersegments 5/6, 6/7, 7/8, 8/9. Between segments 8 and 18, a pair circular areas around setae a and b are observed, except 11 and 12, in which have only one.

Internal anatomy. Anterior septa very fragile: only tiny membranous threads representing the septa are observed between segments 7 and 14. Gizzard rounded, in segment 6. Eight pairs of small extramural, tubularshaped calciferous glands, opening into dorsal region of esophagus in segments 7–14; all glands of similar size, with a small appendage in the distal region highly irrigated with blood; gland structure of composite-tubular type, consisting of short parietal tubules that flow into each other. In the center, the tubules merge together in the lumen from where they branch out toward the tip of the calciferous gland. Esophagus-intestine transition at 18/19, typhlosole beginning in segments 29–30. No caeca. Three pairs of thin lateral hearts in segments 7–9, separating the calciferous glands, and two pairs of voluminous intestinal hearts in segments 10 and 11. One pair of holonephridia per segment, nephridiopores located just above the line of setae c. Two pairs of large hypo-esophageal testis sacs in segments 10 and 11, two pairs of seminal vesicles extending forward in segments 11 and 12. One pair of ovaries in segment 13. Four pairs of spermathecae that increase in size, 9=8>7>6, those of segments 8 and 9 are 1 mm, in line with setae c. In each spermathecae the duct is indistinguishable from the ampulla and they are rod-shaped; no seminal chambers ( Fig. 3D ).

Remarks. Martiodrilus (Maipure) tapiai sp. nov. is a species closely related to M. (Mp.) palmirus ( Zicsi and Feijoo1994) (Palmira, Colombia), the number of segments occupied by the clitellum in 15- ½ 25 (vs. 14–25) and the presence of four pairs of spermathecae in 5/6-8/9 are similar features. However, palmirus differs from the new species in the following characteristics: tubercula pubertatis in segments 1/n 20 - ¼ 25 (vs. 19–24). It also differs in the shape of the spermathecae, shape and size of common setae, ornamentation of genital setae and, the location of male pores in 20/21 (vs. in 18/19).

Figures

FIGURE 3. Martiodrilus (Maipure) tapiai sp. nov. Holotype. A. Common seta, segment 36. B. Genital setae a, segment 15. C. External, ventral view of clitellum and tubercula pubertatis, segments 14–25. D. Spermathecae of 6, 7, 8, 9; Gizzard in segment 6.