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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Martiodrilus

  1. Martiodrilus pano Righi, 1992 (ref. ID; 6019 original paper)

Martiodrilus pano Righi, 1992 (ref. ID; 6019 original paper)

Descriptions

Length 165-173 mm. Middle-body 3.4-3.7 mm dia. Number of segments 251-294. The dorsal colour was violet like No. 90 of Seguy (1936), and the venter whitish, the boundary between the two colours is abrupt on the nephridiopore line, and the clitellum is orange in colour like No. 188. The prostomium is tentaculiform, short and thick. The rudimentary segment I and the prostomium are invaginated in the majority of the worms. Segment II is of normal length and its flabby wall has one pair of nephribuccal furrows. The setae are arranged in 4 pairs of regular longitudinal rows, recognized from V backwards. The setal relations are in the middle-body region (segments L-LX) aa:ab:bc:cd:dd=7.2:1.0:8.4:1.0:25.8 (ab=200 µm) and in the posterior region (CCV-CCXV) aa:ab:bc:cd:dd=9.5:1.0:6.2:0.9:19.1 (ab=220 µm). The common setae are elongated, slightly sigmoid, with distal nodulus, unicuspidate apex and the subapical portion has 4 alternate series of wide and shallow semilunar excavations; there are 3-4 excavations per series. The setae length are 373-501 µm (M=432 µm) in the middle-body and 321-476 µm (M=412 µm) in the posterior region; the shortest setae are dorsal. The ventral setae of IX and from XVIII to XXVI are transformed into genital setae. They are straight with a slight proximal curve; their distal half has 4 series of semilunar excavations that are deeper and narrower toward the apex; there are 9-14 (M=11) excavations per series. The length of the genital setae varies between 1.067-1.350 mm (M=1.220 mm); the longest are in XVIII and XIX. The clitellum lies in XV-XXVI (12 segments); it is turgid with well-marked intersegmental furrows and saddle-shaped with gradual lower margin. One pair of ridges of puberty is in segments XX-1/2XXVI at the side of the line b. The ridges are narrow, not very prominent, with milk-white borders and a mid-longitudinal depression. One pair of tumescences without defined limits are ventral in IX. Circular setal papillae contain each ventral setae of IX and XVIII-XXVI; the papillae of IX are flat, the other crateriform. The first entirely seen septum is 9/10. The septa 9/10-15/16 or 16/17 are infundibuliform, the following are plain. The 9/10-13/14 are thick and muscular, the others get successively thinner to 14/15 or 16/17, remaining uniform backwards. The short pharyngeal bulb terminates in III. One voluminous and fusiform gizzard is situated in the cavity of VI, but due to the septa form it corresponds to parietal segments VIII-IX. Eight pairs of calciferous glands originate ventrolaterally from the oesophagus in VII-XIV. They are reniform, becoming wider and more curved in the rear; their oesophageal side continues in a dorsal finger-shaped appendix. The structure of the glands is honeycomb type (Wabentasche of Michaelsen 1918). In each glands the main axis goes through a central cavity from where short radial tubes depart, which are wider in the side opposite the oesophagus. The transition oesophagus-intestine lies in 17/18. One pair of short and wide intestinal caeca is ventral in XXVII. The dorsal typhlosolis begins in XXVII. In the transverse section it is sigmoid as high as the intestinal diameter. There are 3 pairs of lateral hearts in VII-IX and 2 pairs of intestinal hearts in X and XI. The subneural vessel is present. Each segment has one pair of holonephridia with nephridiopore in the intersegmental furrow or soon after, on line c. Each postclitellar nephridium has one preseptal funnel with a wide horseshoe-shaped upper lip. In the postseptal portion, loop I reaches the nephridiopore line and loop II is single and goes up a little. The region common to loops I and II forms a short medial loop and connects with the ventral extremity of the bladder (loop III) through a glandular sinuous duct widened in the midpart. The large ring-shaped testes sacs in X and XI surround the oesophagus, dorsal vessel, hearts, calciferous glands and also the first pair of seminal vesicles. Sometimes the testes sacs of XI do not merge dorsally, leaving the dorsal vessel free. The two pairs of seminal vesicles are dorsolateral in XI and XII; the second pair is the biggest. The two pairs of vas deferens on each side run together straight along the ventral body wall only to coalesce a little before the male pore located in 20/21 within the corresponding ridge of puberty. The pair of wide fan-shaped ovaries are ventral in XIII. There are no regular rows of ripening eggs; the mature eggs are placed randomly in the ovary margin opposite septum 12/13. Three pairs of voluminous spermathecae are in VII-IX, opening through small pores on line c of 6/7-8/9. In every spermatheca there is no distinction between duct and ampulla; the spermathecae are sacciform, irregularly folded, without seminal chambers and with the larger ental part full of spermatozoa. (ref. ID; 6019)

Remarks

Martiodrilus pano has affinities with M. helleri (Michaelsen, 1918) known in Suriname. They are distinguished by the number of hearts, testes sacs, genital setae and setal rations. (ref. ID; 6019)

Etymology

The name of the new species is that of an indian group from the Peruvian Amazonia. (ref. ID; 6019)

Examined material

Eight clitellate worms (ZU-1240A holotype, ZU-1240B paratypes). (ref. ID; 6019)

Type locality

The worms were collected manually from the soil in Peru, Department of Loreto' Yurimaguas (5 degrees 54'S-76 degrees 05'W) in 1987 and preserved in 10% formalin. The study was made by dissections, pieces mounted in glycerine-water (1:1) and serial histological sections (10 µm) stained by Mallory's triple method (Pantin 1964). (ref. ID; 6019)

Type deposited

The material is deposited in the Department of Zoology, University of Sao Paulo, Brazil. (ref. ID; 6019)