Pleionogaster kitangladensis, James, 2004

James, Samuel W., 2004, New Species Of Amynthas, Pheretima And Pleionogaster (Clitellata: Megascolecidae) Of The Mt. Kitanglad Range, Mindanao Island, Philippines, Raffles Bulletin of Zoology 52 (2), pp. 289-313 : 310

Pleionogaster kitangladensis , new species

( Figs. 4E, F )

Material examined. – Holotype - preclitellate ( NMA 003992 ), Philippines, Mindanao Island, Bukidnon Province, Mt. Kitanglad Range , 8 10.5' N, 124 51' E, 1900 m. elevation, coll. L. Heaney, 22 Mar.1993.

Etymology. – The species is named for the mountain range in which it was discovered.

Description. – Unpigmented, body 75 mm x 2.7 mm (vi), 2.5 (xv), 2.4 mm (xxv); 246 segments; body cylindrical in cross-section. First dorsal pore 12/13; spermathecal pores paired in 7/8, 8/9, 0.16, 0.13 circumference apart respectively, female pore single in xiv, male pores paired in xviii on small papillae, 0.16 circumference apart in 7 th setal line, 6 setae between male pores. Setae regularly distributed around segmental equators; estimated at 170 setae on vii, 78 setae on xx; no dorsal or ventral gaps. Clitellum not developed; genital markings paired on posterior third of xvi, anterior two thirds of xvii, paired presetal in xx, xxi. Nephridiopores not seen ( Fig. 4E ).

Septa 5/6-9/10 thick, muscular, 10/11-13/14 thinner, muscular; remainder thin. Nephridia present as peptonephridia on anterior face of 5/6, micronephridia preseptal vi-ix, on body wall thereafter; from xix 8 micronephridia plus two meganephridia per segment.

Slight muscularity of esophagus in vii, viii; esophagus heavily vascularized, without lamellae xiv-xvi, intestinal origin xix, full size xx, no caeca; thick annular intestinal gizzards xxviixxix; typhlosole 39/40-lvi, simple fold one fourth lumen diameter.

Hearts x, xi arising from esophageal wall, though supraesophageal vessel not visible in those segments, xii esophageal, xiii latero-esophageal, commissural vessels viix lateral. Supra-esophageal vessel xii-xvii, efferent parietoesophageal vessels, extra-esophageal vessels not seen. Small blood vessel runs posteriorly on body wall slightly below midlateral from below esophagous at 16/17 -cxvi, one on each side.

Ovaries and funnels free in xiii, spermathecae paired in viii, ix without nephridia on ducts; each spermatheca with sagittate ampulla with apical knob; short duct differentiated from ampulla, diverticulum stalk arising from duct near duct junction with body wall, diverticulum digitate ( Fig. 4F ). Male sexual system holandric, testes and funnels enclosed in Ushaped sac open dorsally in x, segments x, xi filled with coagulum; testes and funnels free in xi; seminal vesicles xi, xii small, acinous; vasa deferentia extremely small, travel up prostatic ducts to join ental end of prostatic ducts; each prostate a single racemose mass, occupying xviii; with stout muscular duct.

Remarks. – Pleionogaster kitangladensis has testes sacs closed laterally but open dorsally in x, but entirely lacking testes sacs in xi, rather than the single annular or inverted Ushaped closed sacs in each of x and xi as found in all other known Pleionogaster species. It also has a different arrangement of genital markings in the male field from Pl. horsti and Pl. valida , in that it lacks midventral small markings found in Pl. horsti , does not have the sunken male field or the wide midventral marking behind the male pores, of Pl. valida . Other differences from Pl. valida are: fewer gizzards, differentiation of the spermathecal axis into duct and ampulla, single female pore, fewer micronephridia, and fewer setae per segment. On the other hand its spermathecae are differentiated into duct and ampulla as in Pl. horsti .

Figures

Fig.4. Spermathecae, and ventral views showing spermathecal pores, female pores, and male pores of Amynthas heaneyi (A,B), Pleionogaster valida (C, D), and Pleionogaster kitangladensis (E, F). Symbols: fp, female pore(s); mp, male pores; sp, spermathecal pores.