Astacopsidrilus

Astacopsidrilus Goddard, 1909 (ref. ID; 6563, 7264)

Family Phreodrilidae: Subfamily Phreodrilinae (ref. ID; 6563 original paper)

ref. ID; 6563

Phreodriloidinae with the female and spermathecal pore sunk deep within elaborate vestibulae (? with ventral chaetae progressively enlarged posteriad). (ref. ID; 6563)

Type species

Astacopsidrilus notabilis Goddard, 1909 (= Phreodilus (Astacopsidrilus) goddardi Brinkhurst, 1965) (ref. ID; 6563)

Species inquirendae

Phreodrilus mauianus Benham, 1903, Tasmaniaedrilus tasmaniaensis Goddard & Malan, 1913 (ref. ID; 6563)

Astacopsidrilus fusiformis Goddard, 1909 (ref. ID; 6563)
Astacopsidrilus goddardi (ref. ID; 6563)
Astacopsidrilus jamiesoni Brinkhurst, 1991 (ref. ID; 6563 original paper)
Astacopsidrilus naceri Giani & Martin, 1995 (ref. ID; 7264 original paper)
Astacopsidrilus notabilis Goddard, 1909 (ref. ID; 6563)
Astacopsidrilus novus Jackson, 1931 (ref. ID; 6563)

Astacopsidrilus jamiesoni Brinkhurst, 1991 (ref. ID; 6563 original paper)

Descriptions

Dimensions approximate, from preserved, whole-mounted specimens 4-4.5 mm long, 0.6 mm wide. Less than 50 segments. Dorsal chaetae from III, hairlike anteriorly, becoming shorter and more sigmoid posteriorly, single but with paired lateral chaetae. Ventral chaetae paired, slightly dissimilar, 1 clearly bifid with reduced upper tooth, the other apparently simple-pointed in some specimens, both bifid in others. Ventral chaetae progressively enlarged from II-VIII, large in IX-XI, somewhat hooked. Ventral chaetae largest in XXX-XXXV area. No spermathecal chaetae. Body wall (whole-mounted specimens and sections) thrown into deep folds. Prostomium small. Clitellum prominent ventrally on XII-XIII. Genital pores ventral, in the ventral chaetal line of XII and XIII, female and spermathecal pores confluent. Pharyngeal walls as thick and glandular as the gut walls in all seven anterior segments, not especially thick dorsally and without retractor muscles or pharyngeal glands. Gut enlarges in VIII-IX, epithelium less heavily stained in sections. Testes in XI, ovaries in XII. Sperm sacs in X, eggs in XII protrude slightly to XIII. Male ducts each with a small funnel leading to a wide section of vas deferens which is apparently preseptal. Vas deferens coiled, joining effluent duct of atrium before entering penis posteriad. Atrium long, twisted, narrowing ectally. Large pendant penis, deeply recessed in penis sac so that body of penis lies against dorsal wall of XII. Large retractor muscle runs diagonally from in front of penis sac dorsally to insert between the male and female pores ventrally. Spermathecal ampullae dorsal in XIV, ovoid. Sperm in organized bundles in ampulla. Spermathecal ducts with muscular walls and narrow lumina. The spermathecal ducts leave the ampullae and run down to the ventral side of XIII and then ascend to enter the apical (ental) ends of tall vestibulae that open behind the male pore. Each female funnel opens into the anterior aspect of one of these vestibulae just above the insertion of the diagonal muscle band. The ovaries are long narrow structures trapped between the penis sacs and the female vestibulae, with the largest oocytes lying against the body wall dorsally in a small egg sac. (ref. ID; 6563)

Remarks

The subgenus Astacopsidrilus contains two species that inhabit crayfish (goddardi and fusiformis) and one supposedly free-living species (novus). None of these is well described. The dorsal chaetae of goddardi are whiplike, and are certainly present from XXXI to XLIII. Goddard (1909) says "...I have found dorsally situated setae completely enclosed in setigerous sacs, even in the anterior region of the body, but they do not preject beyond the surface, and, judging from their strength of development, are possibly disappearing." These comments could indicate that the dorsal chaetae had simply dropped out and the lateral chaetae were then visible. This is common in phreodrilids. There are dorsal chaetae in fusiformis. Goddard had difficulty describing the spermathecal ducts and female pores, but he does describe thin-walled sacs on the anterior face of XIII which he calls oviducts. The whole description of the spermathecae and their ducts suggests the same pattern as that described for jamiesoni. The spermathecae in both species described by Goddard are said to be composed of two chambers connected by duts. There are paired spermathecal ampullae in jamiesoni but though they are closely applied to each other in the whole mounted specimens, there is no connection between them in the sectioned specimens. The major difference we can see between jamiesoni and the earlier species is that the vasa deferentia and atria are short in the former, and they join basally. In both of the original species, the vasa deferentia are shown as long coiled tubes, much thinner than the atria which they join prior to the narrowing of the atria above the penes. The atria are illustrate as about 14 times longer than broad in both species. As the original publication is not widely available, the original sketches of the male ducts are redrawn in Fig.4. The differences between the male ducts illustrated in Figs.2 and 4 seem sufficient for us to recognize the new material as a new species. Australian crayfish should be examined closely for more of these interesting parasites or commensals. Astacopsidrilus novus is poorly described, largely due to a lack of material (Jackson 1931). This is difficult to be certain as to the proper identification of the original mentioned in the description of the reproductive system. There are supposedly testes in both X and XI, which would be unique to this taxon within the family (but not impossible according to this author's view of the ancestry of oligochaetes from forms with four pairs of gonads). The sperm funnels and vasa deferentia were not observed. There are sperm sacs in ?XVI instead of anterior to the (second pair of) testes, and sacs with grandular material in XIII-XIV which may be egg sacs full of precipitated yolk. There is a large atrium [sic] extending in from the female pores on XIII, just as in A. jamiesoni, and though the spermathecal ampullae are in XIII, the usual thick-walled ducts cannot be traced to their termination in these "atria." The clearest distinction between this species and A. jamiesoi is that there are 2 dorsal chaetae in the dorsal bundles of III (segment II according to Jackson 1931) and 4 or 5 in each bundle of the next 3 segments. The number is reduced from there until XIII (?XIV), when there is 1. If the dorsal chaetae of A. novus really do begin on II, the taxon does not fall within this family. (ref. ID; 6563)

Etymology

For B.G.M. Jamieson, who provided the material. (ref. ID; 6563)

Type locality

Lamington National Park, Queensland, Australia, on an unnamed crayfish, 14 November 1982. (ref. ID; 6563)

Type materials

Holotype: C1-4, QM GH 5062, Queensland Museum, a longitudinally sectioned specimen on four slides. (ref. ID; 6563)

Paratypes: A1-3, B1-4, D1-2, QM GH 5063-5065. (ref. ID; 6563)

Astacopsidrilus naceri Giani & Martin, 1995 (ref. ID; 7264 original paper)

Descriptions

Length of holotype 9 mm, more than 39 segments (no complete specimen observed). Width at segment VIII 0.35-0.42 mm (slightly compressed specimen), width at XI (clitellum) 0.53 mm. Prostomium conical with round tip, 84 µm long, 130 µm wide. Secondary annulation present from II. Clitellum extending over XII-XIII.Ventral setae paired, one bifid, 6.5 µm thick (3.5 µm in one paratype), sigmoid with a slight nodulus, with upper tooth thinner and shorter than lower, and one simple-pointed, thin with inconspicuous nodulus (only 3.4 µm thick, 1.7 µm in one paratype). Size and shape of ventral setae similar throughout body. No ventral setae on XII. Dorsal setae from III, 1 (2) hair seta(e) flanked by 2-4 "support" setae not extending beyond body wall. Anterior hair setae smaller than posterior ones, 7-9 per bundle; when two hair setae present in one bundle, sizes dissimilar (one much shorter). No dorsal setae on XII. Male pores paired in line with ventral setae, opening posteriad in XII in a deep fold of the body wall. Superficial openings of spermathecae paired on anterior margin of XIII. Septal glands present in V-VIII; eversible dorsal pad of pharynx seems weakly developed in whole-mounted specimens (no sections available). Male ducts paired. Prostate gland absent. Sperm funnel small, located in ventral part of septum 11/12. Vas deferens thin, about 12 µm wide, opening into base of atria near union with penis. Atrium confined to XII, tubular, proximal part lying at beginning of vas deferens, running straight up, then bent at an angle, distal part horizontal and directed towards posterior septum of segment. Atrial ampulla 640 µm long, 100 µm wide, with a distinct lumen except in its ental part. Inner epithelium of atrium not ciliated; epithelium cells tall and conspicuous. Proximal part of atrium ending in a true penis opening in a deep fold of body wall. No cuticular penis sheath. Spermathecal duct about 500 µm long, 40 µm in diameter, with narrow lumen, abruptly ciliated of form a globular muscular trap, opening into a deep vestibule attached by strong muscular fibers to ventral body wall of XIII only. Spermathecal ampullae long, about 850 µm, tubular (70 µm wide), and extending from XIII to XV. Sperm organised into thin, elongated bundles, more or less spirally coiled and filling the spermathecal ampullae. Seminal vesicle extending over VII anteriorly and not seen posteriorly. Egg sac extending through XI and XII. Female funnel perceptible as an inconspicuous cell cluster between penis and spermathecal vestibule; opening not observed by probably involved with vestibule because of location of funnel. (ref. ID; 7264)

Remarks

The specimens mentioned under "Other material" are maily immature worms, and included only one mature worm. Because of the mounting medium used, the genital apparatus of the latter is no longer visible. Accordingly, these specimens may not be considered unequivocally to belong to the new species. All external characters, however, are similar to those of the type and paratypes, except for the upper tooth of the ventral setae, which has the same length as the lower in postclitellar segments. Moreover, despite the mounting medium, a similar outline of the spermathecae can be distingished in the mature specimen, the ampullae of which are filled with bundles of sperm organised in the same way as in the type and paratypes. (ref. ID; 7264)

Separation of Astacopsidrilus naceri sp. nov. from its congeners: The presence of hair setae flanked by support setae from segment III in dorsal bundles and the general plan of the reproductive system are typical of the Phreodrilidae. The ventral location of the spermathecal pores authorises us to include this new species in the subfamily Phreodriloidinae as defined by Brinkhurst (1991). To date, the Phreodrilinae includes three genera, Astacopsidrilus, Goddard, 1909, Insulodrilus Brinkhurst, 1991, and Shizodrilus Stout, 1958 (Brinkhurst, 1991). Our new species cannot belong to Schizodrilus, as this genus is characterized by a shift of the reproductive organs by two segments, or loss of the same (Brinkhurst 1991). Astacopsidrilus differs from Insulodrilus in that the female funnel is in the vestibule. This is the only character that defines the former genus unequivocally, but it is very difficult to detect without histological sections. The female funnel of our new species is inconspicuous and its location suggests such an involvement but this observation is uncertain. Nevertheless, the combination with two other characters (not exclusive, however), namely the absence of spermathecal setae and, particularly, the deep vestibules running right up to the dorsal wall of the body, with muscular attachment, permits us to put the new species in the genus Astacopsidrilus with some confidence. Amongst the 10 Insulodrilus species described so far, only 3 indeed have no spermathecal setae (I. breviatria Brinkhurst and Fulton, 1979, I. uniseta Brinkhurst, 1982, and I. campbellianus Benham, 1909). While the first two have only simple-pointed setae in their vental bundles, I. campbellianus has either one simple-pointed and one minutely bifid setae per ventral bundle or two bifid setae in some bundles (bifid in virtually all bundles; A. Pinder, communication in a letter). These characters place this species close to A. naceri sp. nov. (no spermathecal setae, two kinds of setae in at least some ventral bundles). Such a relationship with Astacopsidrilus has already been noted by Brinkhurst (1991). The Insulodrilus-type vestibules are typically small swellings on the end of the ducts and are essentially ventral (R.O. Brinkhurst, personal communication), clearly differing from those of A. naceri sp. nov. The only notable exception is Insulodrilus tanganyikae Brinkhurst, 1970, which has large thin-walled vestibules attached to the body wall dorsally by strong musculature. Originally placed within the subgenus Astacopsidrilus on the basis of similarity of the vestibules (Brinkhurst 1970), this species was later transferred to the Insulodrilus group after reassessment of the taxonomic characters (Brinkhurst 1982). These hesitations attest to the ambiguous position of I. tanganyikae. The recent discovery of a new Astacopsidrilus species, A. jamiesoni Brinkhurst, 1991, clarified the description of the genus. As a result, it becomes clearer and clearer that I. tanganyikae lies neatly between Insulodrilus and Astacopsidrilus. (ref. ID; 7264)

Etymology

The species is named after Dr. Boujemaa Idbennacer (Marrakech), who collected the type material during a study of the groundwater fauna of the Guelmim area in Morocco. (ref. ID; 7264)

Distribution and habitat

To date, the species is known only from groundwaters of Morocco. (ref. ID; 7264)

Type locality

A well on the road joining Guelmim to Ksabi, about 10 km west of Guelmim, Morocco, 80-03-20, coll. B. Idbennacer. (ref. ID; 7264)

Type materials

Holotype: The Laboratoire d'Hydrobiologie, Universite P. Sabatier, Toulouse, France (LHUS), slide, one mature specimen, dissected, stained in alcoholic carmine and mounted in Canada balsam. (ref. ID; 7264)

Paratypes: 7 immature specimens from type locality, stained in alcoholic carmine and whole-mounted in Canada balsam, coll. N. Giani, LHUS; 3 immature specimens from a well in the town of Guelmim, Morocco, 86-04-10, coll. B. Idbennacer; 4 immature specimens from the hyporheic flow of Oued Assaka, west of Guelmim, Morocco, 86-04-10, coll. B. Idbennacer. (ref. ID; 7264)

Other material: 10 immature specimens from a well in the vicinity of Tiznit, Morocco, 86-11-21, coll. M. Boulal; 1 mature specimen in the hyporheic zone of Oued N'Fis, Morocco, coll. M. Yacoubi; 1 immature specimen from the hyporheic zone of Qued Makhfaman, a tributary of Oued N'Fis, Morocco, coll. M. Yacoubi; 2 immature specimens from the hyporheic zone of Zat Valley, Morocco, coll. M. Yacoubi. (ref. ID; 7264)