Taxonomic Revision of the Marine Genus Heterodrilus Pierantoni (Oligochaeta,Tubificidae)1

Marine tubificids possessing trifid anterior setae are morphologically and taxonomically reviewed, on the basis of material from the Atlantic and Pacific Oceans. Heterodrilus Pierantoni, 1902 is revised to include thirteen species, H. arenicolus Pierantoni, 1902, H. minisetosus sp.n.H. ascensionensis sp.n. H. queenslandicus (Jamieson, 1977), H. lacertosus sp.n. H. scitus sp.n. H. keenani sp.n. H. claviatriatus sp.n. H. subtilis (Pierantoni, 1917), H. jamiesoni sp.n. H. occidentalis sp.n. H. pentcheffi sp.n. and H. bulbiporus sp.n. The genus is briefly defined: marine tubificids with trifid setae in preclitellar segments (with H. subtilis as the only exception); paired spermathecae located in segment X; vasa deferentia entering apical, ental ends of slender, ciliated atria, which bear broadly attached masses of prostate glands; paired male pores, and generally with penial setae arranged in bisetal bundles. Heterodriloides gen.n. is established for H. quadrithecatus sp.n. distinguished from Heterodrilus by two main features: its spermathecae are located in XII, with a supplementary pair generally located in XI; and its vasa enter the ectal part of the atria. Giereidrilus gen.n. a third genus with trifid setae, is established to include Phallodrilus ersei Giere, 1979 and G. inermis sp.n. Both species have unpaired spermathecal and male pores, and their atria are not ciliated. Heterodrilus, Heterodriloides and Giereidrilus are placed in the subfamily Rhyacodrilinae Hrabě, 1963.     

Inanidrilus bulbosus gen. et sp.n., a Marine Tubificid (Oligochaeta) from Florida, USA

Inanidrilus bulbosus gen. et sp.n. is described from subtidal sands near Miami, Florida. The species lacks alimentary canal, but it possesses highly modified penial setae and an unpaired dorsal spermatheca. It appears closely related to Phallodrilus Pierantoni, but since it is devoid of anterior prostate glands, which are attached to the ental ends of the atria in Phallodrilus , a new monotypic genus, Inanidrilus gen.n., is established.     

Six new species of marine Tubificidae (Oligochaeta) from the continental shelf off Peru

Six species of marine tubifieids are described from the continental shelf off Peru. Two of them are members of the gutless genus Olavius Erséus, 1984 (subfamily Phallodrilinae). Olavius bullatus sp.n. possesses 2 pairs of large penial setae in voluminous copulatory sacs, tiny atria, and spermathecal pores in line with dorsal setae. Olavius crassitunicatus sp.n. is characterized by small atria with thin muscular layer, spermathecae with short ducts, opening dorso-laterally, and lack of penial setae. Four species arc members of the subfamily Limnodriloidinae. Limnodriloides busilicus sp.n. belongs to the appendiculatus-group (sensu Erséus). It is discriminated by somatic setae with subdental ligaments, and its voluminous elongate prostatic pads. Limnodriloides clavellatus sp.n. is distinguished from its congeners by a peculiar bulge in the cavity of each atrial ampulla, and spermatozeugmata imbedded in the walls of the spermathecae. Tectidrilus intermixtus sp.n. is similar to T. bori (Righi & Kanner, 1979); it is distinguished from the latter by having trisetal bundles in segment V or V-VI and by lacking copulatory glands. Marcusaedrilus peruanus sp.n. is characterized by nongranulated atrial ducts and bipartite spermathecae.     

Three new species of Potamothrix (Oligochaeta, Naididae, Tubificinae) from Fuxian Lake, the deepest lake of Yunnan Province, Southwest China

Three new species of Potamothrix Vejdovsky & Mrázek, 1902 (Oligochaeta: Tubificinae), Potamothrix praeprostatussp. n., Potamothrix paramoldaviensissp. n. and Potamothrix parabedotisp. n., are reported from Fuxian Lake of Yunnan Province, Southwest China. Potamothrix praeprostatusdiffers from its allies by its prostate glands joining atria in its proximal to middle portion, and spermathecal chaetae. Potamothrix paramoldaviensis is distinguishable from its allies by having penial chaeta but no penes, and differs from Potamothrix moldaviensisby its homogenous atrium. Potamothrix parabedoti is distinctive in the position of its reproductive organs, and differs from Potamothrix bedoti by its homogenous atrium. Hitherto, 34 freshwater oligochaete species have been recorded in Yunnan Province, including nine endemic species from the plateau lakes.     

Nine new species of Dichogaster (Oligochaeta, Megascolecidae) from Guadeloupe (French West Indies)

Nine species belonging to two distinct groups within the genus Dichogaster Beddard, 1888 are described from material collected on the volcanic section of the island of Guadeloupe. The species Dichogaster arborea, D. caesitifusca, D. callaina, D. girija and D. basseterrensis all inhabit the leaf tanks of bromeliads and share the following anatomical characteristics: spermathecal pores on the trailing edges of segments, spermathecal axis differentiated into ampulla, internally fluted central chamber and duct, penial setae long and slender, testes and funnels free, prostomium undivided or divided by two grooves, simple single typhlosole and a pair of dorsal caeca on the mid-intestine. Dichogaster athena also inhabits bromeliads, but lacks the above characteristics and male reproductive organs, and is more similar to the remaining species. The three remaining species, D. guadeloupensis, D. matoubensis and D. musciphila , with lateral typhlosoles, no intestinal caeca, simpler spermathecal structure, prostomiums divided by a single groove and short penial setae, all inhabit soils of montane forests. The division of Dichogaster based on muscularity of the proventriculus wall is shown to be unsupportable, since thickness of the wall is size-related.     

A new species of the subterranean genus Krenedrilus dumnicka (Oligochaeta, Tubificidae) from the deep bottom of an oligotrophic caldera lake in Japan

A new tubificid oligochaete, Krenedrilus towadensis, is described from deep bottoms of the oligotrophic caldera Lake Towada in northern Japan. It resembles K. realis Martínez-Ansemil and Collado, 1996, in the combination of somatic setae, but it is different from all other congeners by the lack of spermathecal setae and epidermal papillae in X, in the structures of penial and supernumerary setae, and in the location of spermathecal pores. The definition of Krenedrilus is revised.     

Olavius cornuatus sp.n. (Oligochaeta, Tubificidae) from Georges Bank (NW Atlantic)

Olavius cornuatus sp.n. is described from Georges Bank off Massachusetts. It is distinguished from other species of Olavius Erséus, 1984 by its curved, horn-shaped atria ending in large, protrusible penes and up to six ectally hooked penial setae per bundle.     

New and Little-Known Species of Deep-sea Tubificidae (Oligochaeta) from the North-West Atlantic

Eight species of Tubificidae are reported from deep-sea samples taken south of Massachusetts. Phallodrilus grasslei sp. n., with heavily muscular vasa deferentia, and penial setae, two per bundle, oriented with ectal ends obliquely pointing towards the anterior, and P. rostratus sp. n., with a long and narrow, snout-like prostomium, heavily muscular, tripartite atria, and small, hooked penial setae, about five per bundle, are described. Phallodrilus biparis Erséus, previously known only from off France in the north-east Atlantic, is reported and depicted. Taxonomic notes are provided for Adelodrilus voraginus (Cook), A. fimbriatus Erséus, Bathydrilus asymmetricus Cook, and B. atlanticus Erséus. The depth distribution of all eleven deep-sea tubificid species known to occur south of Massachusetts are briefly discussed.     

Taxonomic Studies of Phallodrilinae (Oligochaeta, Tubificidae) from the Great Barrier Reef and the Comoro Islands with Descriptions of Ten New Species and One New Genus

A taxonomic and morphological account of a collection of Phallodrilinae from coralline sands at Heron Island in Australia's Great Barrier Reef is given. Ten new forms are described: Jamiesoniella athecata gen. et sp.n. Phallodrilus rectisetosus heronensis subsp.n. P. geniculatus sp.n. P. filithecatus sp.n. P. clavatus sp.n. (latter three all devoid of an alimentary canal), Bathydrilus superiovasatus sp.n. Coralliodrilus atriobifidus sp.n. C. oviatriatus sp.n. C. parvigenitalis sp.n. and the gutless C. avisceralis sp.n. Morphological notes are given for Phallodrilus albidus Jamieson, 1977 and Bathydrilus rohdei (Jamieson, 1977). The new meiobenthic genus Jamiesoniella is characterized by having simple atria with only one pair of prostate glands, which are attached to ectal parts of atria, and by lacking spermathecae and penial setae, The genus is probably related to Aktedrilus Knöllner and Bacescuella Hrabě. A gutless species, Phallodrilus comorensis sp.n. is described from the Comoro Islands in the Mozambique Channel (W Indian Ocean).     

Potamothrix scleropenis sp. nov. (Oligochaeta: Tubificidae) from Fuxian Lake, the deepest lake in southwest China

Potamothrix scleropenis sp. nov. (Tubificidae: Tubificinae) is described from the profundal zone (74 m) of Fuxian Lake, the deepest lake (up to 155 m) on the Yunnan-Guizhou Plateau in China. The new species is assigned to Potamothrix because of its short vasa deferentia and its tubular atria without ejaculatory ducts and prostate glands. It differs from congeners by its cuticularized penis sheaths; bifurcated, strongly curved spermathecal chaetae; bifurcated lower prongs of bifids; and feathered hairs. P. scleropenis appears closely related to P. cekanovskajae Finogenova, 1972 and P. tudoranceai Sporka, 1994, since all the three species have homogeneous atria without prostate glands.     

External structures used during attachment and sperm transfer in tubificids (Annelida,Oligochaeta)

The genital region of seven species of Tubificidae has been studied by SEM (Scanning Electron Microscopy). The form and the position of penial and spermathecal chaetae, male and spermathecal pores and other special structures have been examined. Peristodrilus montanus shows a special system to hold the partner: the penial chaetae anchor in an elaborated structure of the body wall formed between the spermathecal pores, the `anchorage bridge'. Protuberodrilus tourenqui has a long glandular porophore with the male pores at the tip, allowing contact with the spermathecal pores which are located in deep, close to the mid-ventral line of the body. The grooved and strongly curved penial chaetae of Rhyacodrilus falciformis seem to be used both for attachment and for sperm transfer, entering into the lateral spermathecal pores. The embrace of the partners, as suggested by observations on Psammoryctides barbatus, Potamothrix bavaricus, Potamothrix hammoniensis and Potamothrix heuscheri, seems to be another important mechanism to fix contact between male and spermathecal pores and allow sperm transfer. The spermathecal chaetae could be interpreted as piercing chaetae with a chemical or mechanical stimulating role. Sensitive cilia near the penial chaetae seem to be used by the three rhyacodrilines studied to find the correct anchorage place. There is a great variety of structures which appear to be used for attachment and sperm transfer in tubificids, and consequently their role in the evolution of the whole family may be profound.     

Taxonomic Revision of the Marine Genera Bathydrilus Cook and Macroseta Erséus (Oligochaeta, Tubificidae), with Descriptions of Six New Species and Subspecies

Macroseta Erséus, 1975 is considered a junior synonym to Bathydrilus Cook, 1970 after examination of the type material of B. asymmetricus Cook, 1970. Bathydrilus is defined mainly by its organization of the male duct: vas deferens entering ectal half of atrium, one prostate gland attached to ectal part of atrium, near entrance of vas deferens, another prostate attached to apical, ental end of atrium. B. atlanticus sp.n., B. hadalis sp.n., B. meridianus sp.n., B. graciliatriatus sp.n. and B. longus sp.n. are described from specimens collected from various parts of the world; most of the species are deep-sea forms. Phallodrilus rohdei Jamieson, 1977 and Phallodrilus adriaticus Hrabe', 1971 are transferred to Bathydrilus , and a Caribbean/Bermudian form is described as B. adriaticus trisetosus subsp.n. The taxonomy and morphology of the different species, including B. rarisetis (Erséus, 1975) comb.n., are discussed. Bathydrilus is included in the sub-family Phallodrilinae. It appears closely related to Phallodrilus Pierantoni, 1902, from which it is distinguished principally by differences in the relative positions of the vasa deferentia, the atria and the prostate glands.     

Specific criteria in Grania (Oligochaeta,Enchytraeidae)

The structure of the penial bulb and male efferent duct system of Grania species may be used in addition to setal pattern and spermathecal shape to distinguish species. Six penial bulb types are distinguished: (1) a simple, small, glandular bulb surrounding the male pore; (2) a small, glandular bulb, with a large, associated, dorso-medial gland mass; (3) a small glandular bulb, medial to the male pore, with an elongate male bursa (the aglandular sac), the vas deferens exitting directly into the invaginated male pore; (4) a glandular bulb with an aglandular sac and a small, cuticular stylet embedded in the bulb, extending from the ectal end of the vas deferens; (5) a glandular bulb and an aglandular sac with a long stylet extending from the vas deferens, through the bulb into the sac; and (6) glandular bulb reduced or absent, with or without an aglandular sac; with a long stylet and other prominent modifications, usually muscular, of the vas deferens. The details of the male duct structure were consistent within specimens grouped on the basis of setal distribution and shape and detailed spermathecal structure. Diverse male duct patterns are found within the polytypic species G. macrochaeta and G. postclitellochaeta. The positions of the spermathecal and male pores in their respective segments are distinctive for some species.     

On the taxonomic status of a Dugesia species from Buenos Aires (Platyhelminthes: Turbellaria: Tricladida)

The taxonomic and distributional statuses of the freshwater planarians of South America are imperfectly understood, and a comprehensive review is sorely needed. The species known from the vicinity of Buenos Aires, Argentina, was first described by Böhmig (1902) under the name Planaria dubia Borelli, 1895. Subsequent authors (Kenk, 1930, 1974; Cazzaniga & Curino, 1987) have cast doubt on this assignation. Some have assigned it to Dugesia anceps Kenk; Hyman (1959) was inclined to regard the Buenos Aires planarian as a geographical variant of Dugesia sanchezi Hyman. A comparison of D. sanchezi from the mountainous region of central Chile with specimens from Buenos Aires confirms that the Argentinian material is a distinct species.The differences between the two species are subtle. The Argentinian specimens are distinctive in their possession of infranucleate epithelia of the atria, penis, and bursal canal, as well as in their penial structure. In both species, the epithelia of the atria and bursal canal are glandular. Those of D. sanchezi are nucleate and their secretions are cyanophilous. In the Argentinian specimens, these same epithelia are infranucleate; but while the secretion of the bursal canal is indeed cyanophilous, that of the atrium is erythrophilous. The presence, in these same specimens, of cyanophilous glands opening into the penial vesicles, and of erythrophilous glands whose secretions contribute to a viscous plug in the ejaculatory duct, suggests a difference in the physiology of copulation.It is apparent that the Argentinian specimens are distinct from D. sanchezi Hyman, and probably they represent a new species, one to be described in detail elsewhere. In any case, Hyman's (1959) suggestion that D. sanchezi occurs near Buenos Aires is mistaken; so also is Cazzaniga's & Curino's (1987) identification of specimens from Buenos Aires as D. anceps.     

Propappidae and aquatic Enchytraeidae (Oligochaeta) from the farthest southeast of Russia

Two mountain streams north and northeast of Vladivostok were studied in 1983–1984. In the Komarovka Stream, a great variety of Mesenchytraeus occurred in the spring zone, among them M. crenobius sp. n. with giant setae in the ventral bundles of VI–VIII and M. vshivkovae sp. n. with numerous spermathecal diverticula. In the stream zone of the Frolovka Stream Cernosvitoviella pensau sp. n., characterized by a complicated penial bulb and a very long spermathecal ampulla, was the dominant oligochaete. Propappus arhynchotus Sokolskaya was the second most abundant oligochaete in this stream. It proved to be a true member of this genus and not synonymous with any other species. These are the first records of aquatic enchytraeids for the Primorski Region of Russia.     

New species of the genus Trichodrilus (Oligochaeta, Lumbriculidae)

Five new species of the genus Trichodrilus are described: Trichodrilus longipenis. sp. n. T: rouchi sp. n. T. capilliformis sp. n. and T. angelieri sp. n. from hyporhcic waters of the Iberian Peninsula and France. and T. bonheurensis sp. n. from superticial waters of France. The new taxa contribute with some new features to an amended diagnosis of the genus: presence of modified penial setae, four pairs of spermathecae, hair-like dorsal setae and glandular pads in the epidermis.     

Marine Oligochaeta from the Koster Area, West Coast of Sweden, with Descriptions of Two New Enchytraeid Species

A total of 28 species of marine Oligochaeta (belonging to the families Naididae, Tubificidae and Enchytraeidae) are reported from eulittoral and sublittoral sediment samples taken in the Koster area on the Swedish West Coast. Lumbricillus algensis sp.n. and Grania ovitheca sp.n. are described and their morphological and taxonomical relations to other enchytraeids are discussed. L. algensis is characterized mainly by its spermathecae, which project into segment VI, and by its very large penial bulbs. G. ovitheca possesses no dorsal setae, the ventral setae being present posterior to the clitellum only, and its spermathecae consist of a narrow duct and a large egg-shaped to oval ampulla, filling most of the coelom of segment V. Four sublittoral species, Limnodriloides barnardi (Tubificidae), Lumbricillus semifuscus, Marionina sublitoralis and Grania roscoffensis (all Enchytraeidae) are reported as new to the Swedish fauna.     

A new earthworm species of the genus Drawida Michaelsen(Oligochaeta: Moniligastridae) from China

A new species of terrestrial earthworms is described as Drawida dandongensis sp. nov. from Dandong, Liaoning, China. It is distinguished from others by a pair of spermathecal pores lie in the ventral of 7/8 intersegmental furrow, and a pair of male pores lie in 10/11 intersegmental furrow, between setae b and c.