Periscolex coreguaje, Alexander Feijoo, M. & Celis, Liliana V., 2012

Alexander Feijoo, M. & Celis, Liliana V., 2012, Earthworms (Oligochaeta: Glossoscolecidae) of the Amazon region of Colombia, Zootaxa 3201, pp. 27-44 : 36-41

Periscolex coreguaje sp. nov.

( Figs. 7–9 C)

Materials. Holotype: Clitellate specimen. Locality: Municipality of Florencia, rural community of Balcanes (01°26’07.3”N, 75°31’27.9”W), altitude: 254 m above sea level. Date: 20 June 2008. Collectors: A. Feijoo, L. Celis. Paratypes: 3 adults, 2 juveniles. Locality: Municipality of Florencia, rural community of Germania (01°24’58.8” N, 75°32’18.9”W), altitude: 254 and 270 m above sea level. Dates: 19 and 20 June 2008. Collectors: A. Feijoo, L. Celis.

Etymology. The new species was named in recognition of and in homage to the Coreguaje indigenous people who live in the southwestern Amazon region, the department of Caquetá, and along the Orteguaza River in Colombia.

Description. Epigeic species with a cylindrical body 36.5 mm long. Diameter of the preclitellar region, 1.9 mm; of the clitellum, 1.5 mm, and of postclitelar region, 1.4 mm (segment 40). The holotype has 109 segments and there is no presence of intersegmental furrows. Paratype: 31.2 mm long and 1.3 mm wide. Number of segments 95. The violet coloring of the body between segments 1 and 6 subtly changes into light brown, while the ventrum has a whitish, unpigmented color. The first two segments are invaginated, with a rounded, elongated prostomium swelling in the middle. The setae are visible from segment 3 on, with a perichaetine distribution and with 32 setae in the mid-body region. Fourteen regularly distributed setae are found in the clitellum between the tubercula pubertatis and 18 are located on the dorsal side ( Figure 7). Regular setae present a strong sigmoid curvature, increasing slightly in thickness after the medial region, and forming a curve in the distal region to end in a tip with a pronounced hook ( Figure 8). Genital setae are invisible. The whitish annular clitellum is found between segments 14– 22 and the tubercula pubertatis between 1/3 17 –½ 22. The genital pores are microscopic; the male are in intersegmental furrow 17/18. The female pores are posterior in 14. The nephridiopores are visible from intersegment 5/6 and are located above the tubercula pubertatis. Three pairs of spermathecal pores are in intersegments 6/7, 7/8, 8/9 at level of the line of nephridiopores.

Internal anatomy. The septa are thin and in the form of delicate membranes. The thick and muscular conical gizzard is found in segment 6.

A pair of calciferous glands opens directly into the esophagus in segment 7. Each gland has a circular contour, somewhat flattened laterally, and two small medial and ventral appendages, with a grooved structure and ample central lumen. In Figure 9 A, the calciferous gland of segment 7 at the right is slightly circular, with oblate borders in the ventral region, containing a long lumen irrigated with several dorsoventral tubes that run irregularly and at different heights. There is a space in the center of the gland where tubes separate into two dissimilar halves.

The esophagus–intestine transition starts in segment 15/16 and the typhlosole originate in segment 19 and consist of a thin lamella located on the dorsal side of the intestine. The presence of intestinal diverticula is not observed in posterior segments. Intestinal content predominately contains abundant plant residues and mucus, although some mineral particles were observed.

Three pairs of tiny thin lateral hearts are in segments 7–9 and two pairs of voluminous intestinal hearts are located in segments 10 and 11. There is a pair of intersegmental holonephridia; each postclitellar nephridium is made up of a single funnel and two bands that run to opposite sides of the funnel ( Figure 9 B).

Two pairs of testis sacs and seminal funnels are located in segments 10 and 11. The testis sacs and seminal funnel of each side rise laterally over the esophagus and then merge. After merging, a pair of seminal vesicles continue running along the dorsal side of the intestine with a band on each side of the dorsal blood vessel from segment 15 to 56, on one side, and to segment 60 on the other. The bands present pronounced irregular intersegmental constrictions in each segment cavity. Pair of ovaries and female funnels is located in the ventral region of segment 13. There are three pairs of spermathecae of almost equal size in segments 7, 8, and 9, with a small duct and an elongated oblong ampulla. The spermathecae measure, respectively, 2.0, 2.1, and 2.0 mm ( Figure 9 C).

Remarks. Periscolex coreguaje is a species closely related to P. columbianus , P. longituberculatus , P. fuhrmanni , P. m u i s c a, P. nevoi , P. saliba , P. sicuani , and P. yuya because of the presence of three pairs of spermathecae, but differs from the abovementioned species in the following characteristics: in the case P. c o l u m b i a n u s in the case of P. longituberculatus , in the position of the clitellum (14–22 versus 15–22) and tubercula pubertatis (1/3 17 – ½ 22 versus 20–25); in the case of P. fuhrmanni , in the distribution of setae (perichaetine versus irregular) and tubercula pubertatis (1/3 17 –½ 22 versus 18–22); P. m u i s c a, in the distribution of setae (perichaetine versus eight regular rows) and in the position of the clitellum (14–22 versus 15–22) and tubercula pubertatis (1/3 17 –½ 22 versus 18–½ 22); in the case P. nevoi in the male pores (17/18 versus 18/19), rows of setae (32 versus 30), in the shape of spermathecae and in ornamentation of the normal setae; in the case of P. s a l i b a, in the distribution of setae (perichaetine versus eight regular rows) and in the position of tubercula pubertatis (1/3 17 –½ 22 versus 18–21); in the case of P. sicuani , in the distribution of setae (perichaetine versus irregular) and in the position of the clitellum (14– 22 versus 15–21) and tubercula pubertatis (1/3 17 –½ 22 versus 17–½ 21); and in the case of P. y u y a, in the presence of 32 dorsovental setae compared with 23–25 irregular ventrolateral setae per segment and in the position of tubercula pubertatis (1/3 17 –½ 22 versus 18–21) (Table 2).

Figures

FIGURE 9. Periscolex coreguaje. A: calciferous gland from segment 7; B: post-clitellar nephridium; C: spermathecae of 6 / 7, 7 / 8, 8 / 9.