摘要:

The fine structure of the stinging cells (nematocytes) and stinging capsules (nematocysts) is described forPolypodium hydriforme.a freshwater coclenterate with a prominent endoparasitie stage in its life cycle. All the nematocysts belong to the type of lesser glutinants (atrichous isorhiza) and fall into three size classes. The internal structure of the capsules is similar in the three classes. A novel type of organization of the cnidocil apparatus of the nematocysts is described. The cnidocil lacks a root fibre and its kinctosome sits directly on the operculum of the nematocyst, so that the entire cnidocil apparatus has a radial rather than bilateral symmetry. It is compared with that of other types of nematocytes and its similarity with the mechanoreccptors of the coelentcratcs is noted. The possible place of thePolypodiumnematocytes in the evolution of the collar receptors of the Metazoa is discussed.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00236.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The triclad family Dimarcusidae contains the speciesRhodax evelinae, Opisthobursa mexicana, O. josephinae, Balliania thetisaeandMitchellia sarawakana.A comprehensive description is given of each of these species, covering external features, alimentary system, reproductive system, life cycle, ecology and distribution. Postulated apomorphies of the Dimarcusidae are (1) a penis bulb with gland cells, (2) horizontal orientation of female genital duct or bursal canal, combined with a dorsal opening of the common oviduct or diverticulum and (3) location of the ovaries at some distance posterior to the brain. The generaRhodax, OpisthobursaandMitchelliaform a monophyletic group, the sistergroup beingB. thetisae.The generaRhodaxandOpisthobursashare a sistergroup relationship. The Dimarcusidae should not be classified among the Maricola, Terricola or Paludicola. The family represents a fourth lineage within the Tricladida and is more closely related to the Paludicola and Terricola than to the Maricola.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00237.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Spirobolbolaimus boucherorumsp.n. (Microlaimidac) andSabatieria maboyaesp.n. (Comesomatidae) arc described, andDorylaimopsis pellucidum(Cobb, 1920) is discussed. Intersex specimens have been found in all three species.Spirobolbolaimus boucherorumsp.n. is characterized by its multispiral amphidcal fovea, number and localization of the cervical setae arranged in six rows posterior to the amphids, and large banana‐shaped sperm.Sabatieria maboyaesp.n., a member of theS. pulchragroup, possesses long posteriorly located cervical setae and long spicule

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00238.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The type species ofSigalionAudouin&Milne Edwards, 1830 (5.mathildae), ThalenessaBaird, 1866(S. edwardsiKinberg, 1856) andEusigalionAugener, 1918(E. vazensis)are re‐examined. Since they were first described all three genera have been variously misrepresented, but are currently distinguished by the presence(Thalenessa;syn.Eusigalion)or absence(Sigalion)of a median antenna. Material examined in the present study indicates thatS. mathildaealso possesses a median antenna.ThalenessaandEusigalionare considered to be junior synonyms ofSigalionand the generic placings of all species attributed to these genera are investigate

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00239.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A hypothesis of phylogenetic relationships within the family Tubificidae is presented, based on a Wagner analysis of morphological characters in the different subfamilies. Two major lincages are recognized. One, including the subfamilies Tubificinae, Telmatodrilinae and Limnodriloidinae, is supported by a synapomorphic ability to form slender spermatozeugmata in the spermathecae; the other, including Rhyacodrilinae (paraphyletic), Phallodrilinae, and the (present family) Naididae, is supported by two synapomorphics, the possession of modified penial setae and numerous coelomocytes (the latter secondarily lost in the Phallodrilinae). Some implications for the classification of the Tubificidae are discussed.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00240.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A detailed study of bisexual populations of stick insects collected near Samandaḡ (southern Turkey) showed that the brown females wereRamulus turcus(Karabaḡ), while males and greenish females morphologically corresponded toR. libanicus(Uvarov) from Mount Carmel. The identity of these two taxa was further supported by egg morphology and structure, which agree with earlier descriptions ofR. libanicus.Karyological analysis furthermore showed a chromosome set of 2n = 30 with an XX‐XY sex‐chromosome mechanism which is unusual for stick insects and has never been described before among Ramulini. This supports the identity ofR. turcusandR. libanicusand we conclude that these Turkish and Mount Carmel stick insects belong to the same bisexual species and that its name should beR. libanicus(

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00241.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Ten new species in three subgenera ofDicyrtomaare described from the Hawaiian Islands. Specimens were received from collections made on Hawaii, Maui, Kauai and Oahu. Species definitions are based on chaetotaxy of head, legs and the circumanal region. In addition, presence or absence of lateral spines (neosminthurid setae) on the parafurcular lobes may assist in grouping species within subgenera. Previous records of dicyrtomids from Hawaii include only one species,Ptenothrix(Papaairioides)daubia(Folsom). The following new species are described:Ptenothrix(Ptenothrix) hawaiicnaeis sp.n.,Ptenothrix(Papirioides)kauaiensissp.n.,P.(Papirioides)serratasp.n.,Dicyrtoma(Calvatomina)sylvestratilissp.n.,D.(Calvatomina)brevifibrasp.n.,D.(Calvatomina)tesselatasp.n., D. (Calvatomina)longidigitasp.n.,D.(Calvatomina)bellingerisp.n.,D.(Calvatomina)madestrissp.n., andD.(Calvatomina)microdentatasp.n.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00242.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Five new Antarctic species and four new genera of dendrochirote holothurians are described:Caespitugo diversipesgen. et sp.n.,Caespitugo citriformisgen. et sp.n.,Microchoerus splendidusgen. et sp.n. (all Cucumariidae),Crucella hystirixgen. et sp.n. (Paracucumidae), andEchinopsolus acanthocolagen. et sp.n. (Psolidae). To includeCrucellain the Paracucumidae a minor change of the family diagnosis was necessary. This change is discussed. The species were caught on the continental shelf of the southern and eastern Weddell Sea. mainly in depths between 200 and 650m. Their systematic status within their families as well as relationships to representatives of other familes are discussed.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00243.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Four new species of antarctic holothurians are described:Bathyplotes rubipunctatussp.n.Bathyplotes fuscivinculumsp.n. (both Aspidochirotida),Achlyonice violaecuspidatasp.n. (Elasi‐podida) andParadota weddellensissp.n. (Apodida). The genus,Bathyplotes, is redefined. The material was mainly collected from the continental shelf of the southern and eastern Weddell Sea, at depths between 225 and 840 m. The systematic status of these new species within the genera, as well as relationships to other species and higher taxa are discusse

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00244.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY