摘要:

Spermatozoa ofMyxinidocotyle californicafrom the hagfishEptatretus stoutiiandof Acanthocotyle lobianchifrom the skateRaja clavatashow a similar ultrastructure: two axoncmes of the 9 + 1 type in parallel with the nucleus‐and one mitochondrion. In the releasedAcanthocotylespermatozoa nucleus and mitochondrion both have a triangular cross‐section. No cortical microtubules are present. The ultrastructure of these two acanthocotylid spermatozoa thus corresponds to sperm pattern 2 according to Justineet al.(1985). This pattern is derived from the more primitive pattern 1, which in the Monogenea is found only in the Oligonchoinea Bychowsky, 1937 or the PolyopisthocotyleasensuJustineet

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00245.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Gibson's (1988) reclassification of the class Enopla (phylum Nemertea), and in particular the forming of the taxon Paramonostilifera, is assessed by a cladistic analysis based on 35 characters. This analysis does not support the reclassification, and it is suggested that the previous classification is kept for the time being, although it is recognized that certain of the higher categories are non‐monophyletic and should be reclassifie

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00246.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Both traditional and cladistic taxonomists rely for their analyses upon the same basic data obtained from comprehensive anatomical descriptions of individual species. For nemerteans these data arc at present inadequate, and attempts to devise classificatory schemes based on cladistic studies are not realistically feasible when so many of the individual taxonomic units to be analysed contain unidentifiable polyphyletic groups.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00247.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A new genus and species of Kinorhyncha from the Bay of Vestar (northern Adriatic Sea) is described. The single male specimen was collected from suhtidal medium‐grained sand. Autapo‐morphies ofAntygomonas incomitatagen. ct sp.n. are the occurrence of 32 interstitial placids, three lateral spines on the 10th zonitc, the subdorsal sculpture on the 12th zonitc, two mid‐dorsal spines on the 13th zonitc, and a special cuticular formation of the trunk zonites 4‐13 which show a mid‐ventral articulation zone but no lateral ones. The relationships ofAntygomonas incomitatawithin the Cyclorhagida are discussed. The term zonite (instead of segment), introduced by Zelinka (1928) for the repetitive arrangement of the cuticle, epidermis, nervous system, sense organs, and muscles in Kinorhyncha is

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00248.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The Sabellidae polychaete genusFabriciolaFriedrich is revised as a result of examination of as much of the type material as possible. The type species for the genus has been confused. The earliest designation appears to beFabricia (Manayunkia) spongicolaSouthern, 1921, by Ushakov [Akad. Nauk. SSSR, Opredeliteli po Faune SSSR 56:1–445 (1955)], whereas subsequent works have incorrectly referred toManayunkia pacificaAnnenkova, 1934, as the type species. The following species are redescribed:Fabriciola balticaFriedrich, 1939,F. berkeleyiBanse, 1956,F. ghardaqaBanse, 1959a. A new species,F. mediaseta,is described. A neotype is designated forF.baltica.Existence of the type material of F.spongicola(Southern),F. pacifica(Annenkova), andF. tonerellaBanse, 1959bis unknown, but these species are discussed in relation to species examine

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00249.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A syllid species new to science is described from intertidal sandy sediments on the cast coast of India, for which a new genus is erected:Psammosyllis aliceaegen. et sp.n. Incorporation into either the Eusyllinae or the Exogoninae is unresolved, because it possesses characters of both of these poorly defined subfamilies.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00250.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Specimens ofMiscellania dentatagen. et sp.n. were collected in Catalunya, the Balearic Islands, and Strait of Gibraltar. They are characterized by an anterior tooth and an incomplete crown of denticles on the tip of the pharynx, short and smooth antennae and cirri, bases of palps separated, and the presence of compound and simple setae. Specimens were found living inside calcareous algal concretions.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00251.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Principal component, and canonical variate analysis based on six characters show that there are morphological differences between threeLaoniceforms(L. bahusiensis, L. sarsi,andLaonicesp.). This supports Söderström's divisionof L. cirratainto four species; a decision often questioned by other taxonomists. We cannot exclude the possibility that the morphological differences are caused by polymorphism or seasonal variation within a single species. There is, however, no information to vindicate this and we conclude that the three forms should be regarded as separate species until this hypothesis can be rejecte

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00252.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Radulae have been examined of juvenile specimens of 18 species belonging to the Turbinidae, the Tricoliidae. and 6 subfamilies of Trochidae. The investigations show that all species pass through profound changes, usually finishing at a size of 1.5–3 teleoconch whorls. Most species have an identical, shared morphology at a size of up to 1.5–2 teleoconch whorls, except the species of Calliostomatinac and Solariellinae. The evolutionary consequences are discussed and it is suggested that such an unspecialized starting point means a high potential for specializations and future evolution. For the taxonomist this means a reduction in the reliability of radular differences as a systematic t

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00253.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Spermatozoaof Sinezonasp. (Scissurcllidac) arc examined ultrastructurally and compared with spermatozoa of other vetigastropods.Sinezonasperm are characterized by the following features: (1) a squat‐conical acrosomal vesicle; (2) subacrosomal deposits–one forming a perinuclear sheath and the second forming a rod which almost penetrates the nucleus; (3) prominent nuclear invaginations enclosing the axial rod and centriolar regions; (4) a midpiece consisting of axoneme surrounded by a single, sleeve‐like mitochondrion; (5) an annulus occurring posterior to the midpiece; and (6) a flagellum. Spermatozoa ofSinezonasp. are clearly modified in structure in comparison with spermatozoa of other pleurotomarioids and, more generally, most other vetigastropods (these retain multiple, spherical mitochondria and, with rare exceptions, do not have the ccntrioles located in a nuclear invagina

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1990.tb00254.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY