Andiorrhinus (Meridrilus) timotocuica

Feijoo, Alexander, Brown, George G. & James, Samuel W., 2017, New species of Andiorrhinus Cognetti, 1908 (Oligochaeta: Rhinodrilidae) from Venezuela and Brazil, Zootaxa 4363 (1), pp. 55-78: 66-67

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Andiorrhinus (Meridrilus) timotocuica

sp. nov.

Andiorrhinus (Meridrilus) timotocuica  sp. nov.

( Figure 5A –CView FIGURE5, Table 2)

Material examined. Holotype: Clitellate specimen (MZUSP 01479). Paratype 1: 1 adult ( MZUSP 01480View Materials). Locality: Venezuela, state of Mérida, Mount Zerpa (08°37'N, 71°09'W). Altitude : 2200 m a.s.l. Collection date: 20 July 1996. Collectors: Pedro Durant and E.J. ArellanoGoogleMaps  . Paratype 2. 1 fragmented adult ( MZUSP 01481View Materials). Locality: Venezuela, state of Mérida, forest of Psidium caudatum ( Myrtaceae  ), beside the Núcleo Universitario " La Hechicera ”, Universidad de Los Andes (08º38'00"N; 71º09'30"W). Altitude : 1950 m a.s.l. Collection date: 18 April 1994. Collector: Pedro Durant.GoogleMaps 

Etymology. The new species was named in honor of the indigenous community Timoto-cuica that inhabits the states of Mérida, Táchira, and Trujillo in Venezuela.

Description. Epiendogeic species, with brown-colored dorsum and light brown clitellum and ventral region, corresponding to the respective color code numbers 703 and 705 ( Seguy 1936), and cylindrical body. Holotype: The length of the preserved holotype is 149 mm, with a diameter of 3.6 mm in the preclitellar region, 5.3 mm in the clitellum, and 2.3 mm in the postclitellar region. Number of segments: 202. Paratype: 136 mm long and widths of 3.0 mm (segment 9), 3.7 mm (segment 19), and 1.9 mm in segment 30. Number of segments: 186. The first and second segments are visible and the long, tentacular-shaped prostomium measures 3.2 mm. Four pairs of closely paired setae are visible as of segment 5. The hook-shaped common setae measure 0.46 mm, with no ornamentations ( Fig. 5AView FIGURE5). The distance between the setae in segment 40 is aa:ab:bc:cd:dd = 5.0:1.0:4.3:0.8:13.5 and, in the posterior region in segment 84, is similar to that of segment 40, varying only in cd (0.8) and dd (13.7). The setae of segments 7, 8, 9, and 19–23 are transformed as genital setae which are contained in long follicles that extend to mid-dorsal and are located adjacent to five pairs of glandular masses in segments 19–23,. Genital setae measure 2.36 mm, are rectilinear and, in the apical ½, present 16 U-shaped ornamentations that end in a spearshaped tip ( Fig. 5BView FIGURE5).

The saddle-shaped clitellum measures 9 mm and lies in segments 16–25 (=10), with the tubercula pubertatis located between segments ½19 and 19–23 (=4, 4.5). The male pores are located in intersegment 19/20 and female pores in segment 17, close to rows of setae b. The nephropores are aligned with setae c and d. Three pairs of spermathecal pores were observed in intersegments 6/7, 7/8, and 8/9, aligned with setae c and d.

Internal anatomy. The septa of segments 6/7–10/11 are fine, transparent membranes, septa slightly thicker between segments 11/12–13/14. The round muscular gizzard and thick, disc-shaped musculature are present in segment 6. Three pairs of large, digitiform calciferous glands with internal lamellar structure are present in segments 7–9, with no appendage in the ectal region; each gland with 24–26 parallel lamellae. The transversal cut of the gland shows that two branches exit the ental region, dividing lamellae into three clusters: one proximal to the border, another central, and another in 2/3. The esophagus-intestine transition begins in intersegment 22/23 and the S-shaped typhlosole begins in segment 23, occupying 1/3 of the intestinal lumen. There are no intestinal caeca. Intestinal content consists mostly of very fine organic matter and trace amounts of minerals. Three pairs of lateral hearts are located in segments 7–9, covering the calciferous glands, and two voluminous intestinal hearts are present in segments 12 and 13. Both supraesophageal and subesophageal vessels are present. There is one pair of holonephridia per segment.

Two pairs of testis sacs enclose the testes in segments 10 and 11, and two pairs of seminal vesicles are present in segments 11 and 12. The two pairs of deferent ducts open towards the male pore in intersegment 19/20. One pair of ovaries is present in the cavity of segment 13; the female pore is located in segment 17. Three pairs of small, equal-sized spermathecae, measuring 1 mm, are present in segments 7, 8, and 9 ( Fig. 5CView FIGURE5). The sperm duct is invisible and presents a constriction near 1/3 of the length up from the body wall, that separates the seminal chambers from the ampulla, which is slightly oblong with irregular borders. A group of larger-sized bifurcated genital seta glands are located near the base of each spermatheca.

Remarks. Andiorrhinus (Meridrilus) timotocuica  sp. nov. is closely related to A. (Meridrilus) boconius Righi, 1989  due to the location of male pores in 19/20, and the presence of three pairs of spermathecae in 6/7–8/9. The new species differs from A. boconius  by the extent of the clitellum ( Table 2), the shape of the calciferous glands, the number of lamellae in the calciferous glands, as well as the shape of the spermathecae, shape and size of the normal setae, and ornamentation of the genital setae.