Righiodrilus lebrijae, Celis, Liliana V. & Rangel-Ch, Orlando, 2015

Celis, Liliana V. & Rangel-Ch, Orlando, 2015, Two new earthworm species (Oligochaeta: Annelida) of the Caribbean region of Colombia, Zootaxa 3974 (1), pp. 106-114 : 111-113

Righiodrilus lebrijae sp. nov.

Figure 3 , Table 2

Righiodrilus sp. nov.: Celis & Rangel.-Ch. 2013: 488f., fig. 268.

Material examined. Holotype: LVCelis007, clitellate specimen; Colombia, Department of Cesar, Aguachica, Barranca Lebrija, Doña María wetland (73°43'49.6''W 8°4'47.9''N), 50 m asl; L.V. Celis, 13 November 2011. Paratypes: LVCelis006, 42 specimens (27 adults, 15 juveniles); Colombia, Department of Cesar, Aguachica, Barranca Lebrija, Doña María wetland, 45–53 m asl; L.V. Celis, November 2011. LVCelis003, 36 specimens (28 adults, 8 juveniles); Colombia, Cesar, San Martin, Terraplen, El Congo wetland (73°38'42.6''W 7°52'48.7''N), 58–59 m asl. L.V. Celis, August 2011.

Description. Body cylindrical, without pigment. Body dimensions, holotype: length 65 mm, diameter 1.95 mm in preclitellar region, 3.1 mm at clitellum, 1.9 mm in postclitellar region (segment xl), 133 segments; paratypes: length 60.7–70 mm, diameter 1.8–3.5 mm, 112–135 segments. Setae visible from segment iii; closely paired, 8 per segment, in two ventro-lateral and two latero-dorsal rows. Setae slightly sigmoid without node. Genital setae not found. Distance between setae in mid-body region (segments xl–l) aa: ab: bc: cd: dd = 25: 1.0: 5.0: 1.0: 32.5 (holotype). Clitellum saddle-shaped with barely defined margins in segments xv–xxi; tubercula pubertatis in ½ xvi –½ xix ( Fig. 3 A). Male pores in intersegment 17/18, female pores in segment xiv. Spermathecal pores visible in 8/9 and 9/10. Nephridiopores above setae b visible from intersegment iv.

Internal anatomy. Septa 7/8–10/11 thick and muscularized. Gizzard strongly muscularized, rounded, in segment vi. One pair of extramural, pyriform calciferous glands with tubular structure ( Fig. 3 B) emerging from postero-lateral region of esophagus of segment xi and extending to segment xiv; glandular part in segments xi, xii, membranous part in segments xiii, xiv ( Fig. 3 C). Transition of esophagus-intestine in segment xiii. Typhlosole simple, from segment xiv, occupying 1/3 of gut diameter, folded between segments xiv–xxi, with folds decreasing in number and size from segment xxii to l. Caeca absent. Three pairs of lateral hearts in segments vii, viii and ix, and two pairs of voluminous intestinal hearts in segments x and xi. One pair of holonephridia per segment ( Fig. 3 D). Male funnels free in segment xi and connected to deferent ducts. One pair of seminal vesicles from segment xii, extending backwards along the lateral body region to segments xxix, xxx, or xxxi. Male ducts run along the body wall down to 17/18. Ovaries in segment xiii. Two pairs of spermathecae in intersegments 8/9, 9/10; anterior spermathcae with long duct and rounded ampulla, posterior spermatheca with oval ampulla ( Fig. 3 E).

Etymology. The species is named after the Lebrija River, which flows into several wetlands in southern Cesar, Colombia.

Habitat characteristics. Righiodrilus lebrijae sp. nov. was collected in three physiognomic types of vegetation (relicts of tropical dry forests and savannas and herbaceous plant formation with trees) in El Congo and Doña Maria wetlands, but not in highly transformed areas ( Celis & Rangel 2013).

Comments. Zicsi (1995b) separated the genus Righiodrilus from the genus Glossodrilus Cognetti, 1905 by two major criteria, one being taxonomic (the genus Righiodrilus has a membranous part in the calciferous gland) and the other one referring to its geographical distribution: species of Righiodrilus are found in Brazil, Colombia, Ecuador and Venezuela in rainforests below 1000 m asl, whereas species of Glossodrilus are found above 1000 m in altitude ( Feijoo & Celis 2010). The new species belongs to a group of species of Righiodrilus with two pairs of spermathecae in intersegments 8/9–9/10. Righiodrilus lebrijae sp. nov. is close to R. paolettii Righi, 1984a , R. arapaco Righi, 1982 , and R. itajo Righi, 1971 , in the position of the clitellum. Within this group, the new species has the same extension of the clitellum as R. paolettii (xv–xxi), but differs in the extension of the tubercula pubertatis (3 segments vs. 2 ½ in R. paolettii ), the extension of the seminal vesicles (xxix, xxx, or xxxi vs. xxvi in R. paolettii ), the position of the male pores (17/18 vs. anterior part of segment xvii in R. paolettii ), the arrangements of setae (closely paired vs. widely paired in R. paolettii ) and in the shape of the spermathecae (anterior spermathecae with long duct and rounded ampulla, posterior spermatheca with oval ampulla vs. long duct and arrow-shaped ampulla). A comparison of Righiodrilus species with two pairs of spermathecae is given in Table 2 .

Figures

FIGURE 3. Righiodrilus lebrijae sp. nov. A. Ventral view. B. Calciferous gland. C. Internal dorsal view (Gp, glandular part of the calciferous glands; Mp, membranous part of calciferous glands; Sv, seminal vesicle). D. Nephridium. E. Spermathecae.

Tables

TABLE 2. Comparison of species of the genus Righiodrilus with two pairs of spermathecae in segments 8 / 9 – 9 / 10.

Species	Length (mm)	Clitellum	Tubercula pubertatis	Posterior extension of seminal vesicles	Male pores
R. arapaco Righi, 1982	45–60	½ xvi–½ xxii (6 segments)	½ xviii–½ xx (2 segments)	to segment xiv	19/20
R. itajo Righi, 1971	38–74	xv–xxii (8 segments)	½ xvi–½ xviii (2 segments)	to segments l–lviii	16/17
R. mairaro Righi, 1982	60–115	½ xvi–½ xxii (6 segments)	½ xviii–½ xx–xx (2,2½ segments)	to segments xxiv–xxxvi	18/19
R. oliveirae Righi, 1982	180–250	xv–xxiv (10 segments)	⅔xviii–xx (2⅔ segments)	to segment xiv	⅔19
R. paolettii Righi, 1984 a	30	xv–xxi (7 segments)	xvii–½ xix (2 ½ segments)	to segment xxvi	17
R. lebrijae sp. nov.	60.7–70	xv–xxi (7 segments)	½ xvi–½ xix (3 segments)	to segments xxix,xxx–xxxi	17/18