Zapatadrilus montezumensis Cervantes & Fragoso

Cervantes, Gabriela, Fragoso, Carlos, Monteros, Alejandro Espinosa De Los, Sánchez-Ramos, Gerardo, Lara-Villalón, Manuel, Yañez-Pacheco, Manuel De Jesús, Lázaro-Castellanos, Jesús Omar & James, Samuel W., 2016, New species of the earthworm genus Zapatadrilus (Clitellata, Acanthodrilidae) from northern Mexico, Zootaxa 4189 (2), pp. 311-326 : 317-321

Zapatadrilus montezumensis Cervantes & Fragoso , sp. nov.

( Figures 3 , 4 B,E)

Localities and material. MEXICO, Tamaulipas: (1) Old royal highway Victoria – Jaumave (deviation toward the balcony of Montezuma). Protected Natural Area " Altas Cumbres ". Municipality of Ciudad Victoria. Cloud forest. N 23 ° 35'11.43'', W 99 ° 13' 3.72, 965 m asl ( Fig. 6 A,C). September 18th, 2013. Collectors G. Cervantes, M. Lara- Villalón, O. Lázaro & G. Sánchez-Ramos.

Holotype. One clitellate adult, IEOL4485. Complete specimen, last segments amputated to obtain DNA.

Paratype. One complete clitellate adult, IEOL4484 (DNA sample available).

Additional material. Three incomplete juveniles, IEOL4486 (DNA sample available), IEOL4483 and IEOL4487 (without DNA sample). One incomplete clitellate adult, anterior 30 segments, IEOL4482.

Description. External. Length 56–82 mm (mean= 84 mm, n= 2; holotype 82 mm); postclitellar width 4.5–4.9 mm (mean=4.7, n=2; holotype 4.5 mm). Segments 162–165 (mean=163.5, n=2; holotype 162). Colour white. Prostomium closed epilobous, covering half of 1st segment. Secondary annulation: dorsal postsetal in 7 and 8; one presetal and one postsetal in 9–13, and all postclitellar segments. Setae eight per segment, present from segment 2, closely paired hardly visible. Setal formula in anterior region (aa:ab:bc:cd:dd) in 10: 2.4:1.0:4.0:1.1:7.0; in 30: 3.8:1.0:4.5;1.5:9.0. Genital and penial setae absent. Annular clitellum vermilion dorsally in 1/2 13 –18, ventrally in 1/2 13 –1/2 18, interrupted in 17 by the genital area in AA ( Fig. 3 A). Dorsal pores present all along the body, first pore in 12/13 (all specimens). Spermathecal pores paired and minute in 7/8 and 8/ 9 in A, respectively. Female pores in 14, presetal and slightly median to A, almost mesial, within an ovoid papilla not reaching AA ( Fig. 3 A). Two pairs of prostatic pores in 18 and 20 in B. Male pores in 19 in B. Male genital area square-shaped, in 18– 1/2 21. Three unpaired mid-ventral genital markings in 10, 11 and 12, rectangular shaped, extending beyond B (3 ind.) ( Fig. 3 A). Two rectangular unpaired and mid-ventral markings in 20 and 21. Swellings in 3/3 7, 1/3 8, 3/3 8, and 1/3 9 (one ind.). Holotype with the three genital markings of 10, 11 and 12.

Internal. Septa in 5/6–12/13 thick, muscular and funnel shaped. Two gizzards, in 5 and 6, largest in 6; both gizzards preceded by a thin-walled esophagus. Mesentery covering esophagus of 7 and 8. Lamellae surrounding lining inner wall of esophagus in 10 completely. Calciferous glands absent. Intestine beginning in 17/18 (3 ind.). Intestine with simple typhlosole, a thin line from 32 to 72. Lateral typhlosoles absent. Intestinal caeca absent. In 18–32, the intestine with a pebbly appearance. Single dorsal vessel visible throughout. Supra-esophageal vessel visible in 10–12. Lateral hearts in 6–9. Latero-esophageal hearts in 10–12. Ventral vessel present. Plectonephridia present, over 50 per segment (observed in segment 30).

Metandric. One pair of testes in 11, attached to iridescent male funnels by abundant coagulum. Small, noniridescent, male funnels in 10. One pair of racemose - shaped seminal vesicles in 12. Two pairs of tubulo-racemose prostates of similar size in 18 and 20, tongue-shaped and with a central duct ( Fig. 4 B, E); muscular duct narrower and shorter than glandular part. Retractor muscles in 17–22. Male ducts intraparietal. Ovaries one pair in 13, arbuscular. Two pairs of spermathecae with sessile diverticulum, in 8 and 9 (2 ind.), opening to spermathecal pores in 7/8 (the anterior ones) and 8/9 (the posterior ones). Holotype with anterior spermathecae in 7, with duct opening in 7/8, posterior spermathecae located in 8 (on the right side) and 9 (on the left side), both with ducts opening in 8/ 9. Each spermatheca with an ellipsoidal ampulla, and a sessile ringed diverticulum with multiple chambers, which surround the ental part of the duct ( Fig. 3 B–E).

Etymology. The name makes reference to the archaeological site called "Balcón de Montezuma", which is located near the type locality. The similarity with the name Moctezuma (the most famous Aztec emperor) might wrongly suggest an expansion of the range of the Aztecs in northern Mexico; however "Montezuma" is the customary name that the old Spanish friars used for all prehispanic monuments.

Remarks. Most similar to Zapatadrilus montezumensis sp. nov. is Z. huastecus . Both species are separated by the testes (one pair, metandric vs. two pairs, holandric). Differences between Z. montezumensis and the other species of the genus are presented in Table 1.

TABLE 1. Morphological comparison between species of the genus Zapatadrilus.

Species Colour Prostomium First dorsal Genital markings Penial Spermathecal Testes Prostates Location of Intestine Typhlosole Last pore setae ampullae location prostates beginning hearts Character uncertain ( Eisen 1900, 205: "The sacculate intestine seems to begin in XIII").

Character uncertain ( Gates, 1973, 23: "Prostates with slightly convex but never flat upper and lower surfaces that have a pebbled appearance as if composed of numerous quite small and closely crowded lobules. Structure obviously is not of the simply tubular type but further characterization must await study of microtome sections and of development").

Figures

FIGURE 3. Zapatadrilus montezumensis sp. nov. Paratype IEOL 4484. A. Anterior region of specimen, external ventral view. B, C. Right spermatheca from segment 7: dorsal view (B) and lateral view (C). D. Right spermatheca from segment 8, ventral view. E. Left spermatheca from segment 9, ventral view. Am = Ampulla, Di = Diverticulum, Du = Duct. Gm = Genital marking, Gp = Genital papilla. Scale bar 1 mm.

FIGURE 4. Right prostate glands of segment 18 of the three new species. A – C. External appearance, dorsal view, photograph. D – G. Cross section, scanning electron micrographs. A, D. Zapatadrilus aurelius sp. nov. B, E. Zapatadrilus montezumensis sp. nov. C, F, G. Zapatadrilus huastecus sp. nov. In external appearance (A – C), the prostates of the three species are racemose, but internally (D – G), the cross sections reveal the presence of a single central duct; therefore the prostates are tubulo-racemose. The central duct is indicated by a red arrow. Scale bars = 100 µm (D, E), 50 µm (F), 10 µm (G).

FIGURE 6. Sites of distribution of Zapatadrilus huastecus sp. nov. and Zapatadrilus montezumensis sp. nov. A. Sierra Altas Cumbres, Tamaulipas, within the biogeographical region of Sierra Madre Oriental. B. Oak forest, type locality of Z. huastecus. C. Cloud forest, type locality of Z. montezumensis. (Colour images only in electronic version).