Dichogaster

James, Samuel W. & Gamiette, Franciane, 2016, New species of Dichogaster Beddard, 1888 (Clitellata: Benhamiidae) with additional records of earthworms from Guadeloupe (French West Indies), Zootaxa 4178 (3), pp. 391-408: 399

publication ID

http://doi.org/10.11646/zootaxa.4178.3.5

publication LSID

lsid:zoobank.org:pub:51B86192-BF51-444F-8C00-960C10E8DF5C

persistent identifier

http://treatment.plazi.org/id/440C87AD-FF9E-C958-FF19-C399FCAEF8E9

treatment provided by

Plazi

scientific name

Dichogaster
status

 

Dichogaster  sp. 5

Material examined. 3 late juveniles (one in alcohol), Monts Caraibes trail, Vent Soufflé in bromeliad leaf axils, Basse Terre, Guadeloupe, N15°58.496', W61°41.263', 629 m asl.GoogleMaps 

Description. Dimensions 42–45 mm by 2–2.2 mm at segment x, 2.5 mm at xxx; body cylindrical throughout, segments>102; one amputee at 102, one regenerate from 81 plus 44 regenerated segments. Setae all ventral, closely paired throughout; setal formula AA:AB:BC:CD= 4:1:4:1 at xxx; DD = 2/3 circumference. Prostomium schizolobous, furrow 1/2 obliterated; light olive brown dorsal pigmentation darker anteriorly; residual green color on first 3 or 4 segments in formalin preservation. First dorsal pore 10/11, 11/12; spermathecal pores not seen. Ovipores equatorial median to A in xiv; male pores not seen; prostatic pores at ends of straight grooves in A in xvii –xix; grooves straight. Clitellum not developed, no other genital markings.

Septa 8/9–13/14 slightly muscular, maximal at 11/12; septa 10/11, 11/12 fused at body wall. Alimentary canal with proventriculus in v, two long gizzards in vi, vii; esophagus valvular in xviii, intestinal origin xix; deeply sacculated xix –xxvi; typhlosole a simple thick fold originating in xxv, height one fifth lumen diameter, continuous very low lateral typhlosoles 25/26–xxx, typhlosole ends> xcii, or in cxi in regenerated segments. Calciferous glands reniform, paired in xv –xvii, composed of longitudinally-oriented lamellae opening to medial lumen; each gland with separate duct to esophagus; glands xv<xvi≤xvii. Micronephridia 10 per segment, pre-intestinal nephridia tubular; intestinal segment nephridia closed sac-shaped with oil droplets; median rows of posterior segments with nephrostomes; median row less mantled and with 3 or 4 lobes; no nephrostomes seen anteriorly; nephridia distributed AB-dorsum. Vascular system with ventral trunk, single dorsal trunk, these connected by commisural vessels in viii, ix, latero-esophageal hearts in x –xii. Commissural vessel of vii to gizzard.

Ovaries in xiii; paired spermathecae in viii, ix, juvenile state showing spherical ampulla and small spherical sessile diverticulum. Male sexual system juvenile, testes of x in sub-esophageal sacs, formed by fusion of septa 10/ 11, 11/ 12 in xi; very small tubular prostates in short zig-zags; penial setal follicles and penial setae undeveloped.

Remarks. Although not quite adult, the combination of pigmentation, number of nephridia, shape of prostomium and extent of the lateral typhlosoles distinguishes this species from the other acaecate Guadeloupe Dichogaster  . Dichogaster  sp. 4 has the same number of nephridia, but it is unpigmented, epilobous, the typhlosoles commence more anteriorly and it lives in soil as an endogeic earthworm.

The following new records all are based on adult material except where noted. The number in parentheses preceding the latitude is the number of individuals collected.