摘要:

Anatomical, developmental, and functional studies have demonstrated that the protostone Phoronida (Tentaculata/Lophophorata) share several characters in common with more primitive deuterostomes, thus belonging to the Oligomera and suggesting a level of direct connection between higher (coelomate) Gastroneuralia and lower Deuterostomia. In reevaluation of the characters of the cleavage, the tentacle apparatus, the mesoderm‐coelom organization, the nervous system, and also the fate of the blastopore, there is essential support for an evolutionary differentiation of bilaterian animals along a monolinear sequence of recent megagroups (in contrast to other theories): As still reflected by the Phoronida, such monolinear pathway from mesenchymatous to coelomate Gastroneuralia (Spiralia) to Heteroneuralia (Oligomera) to Notoneuralia (Chordata) was made possible predominantly by decisive paedomorphic processes for the tentacles and the nervous system in gastroneuralian pre‐Heteroneura

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00519.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The genusForticulcitawas established solely forF. glabrasp. n. fromValamugil seheli(Forsskål) in the Gulf of Aqaba. Most closely related toHaploporus, it is diagnosed primarily by having a species with an acetabulum being conspicuously robust, prepharynx measuring shorter than the pharynx, ceca terminating at the testicular level, muscular hermaphroditic ejaculatory organ lacking accessory structures, and vitellarium consisting of a single mass

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00520.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The morphology of the sporocyst and metacercarial stages ofLeucochloridium(Leucochloridium)variaefromSuccinea ovalisin Nebraska, U.S.A., as revealed by light microscopy is described, These results are compared with earlier Holarctic larval descriptions of the brown‐banded broodsac complex. The adult morphology as revealed by light and electron microscopical studies on experimentally reared adults fromLarus canusandTaeniopygia guttatais described and compared with earlier information on this and other species described within the same species complex. No significant differences were found within the Nearctic, or between the Nearctic and Palaearctic material, which imply thatL. variaeMcIntosh (and sensu Lewis),L. priceiMcIntosh, the “Rensselaerville‐sporocyst” described by Ingram&Hewitt,L. fuscostriatumRobinson,L. perturbatumPojmanska,L. subtilisPojmanska,L. fuscumRietschel, andLeucochloridiumsp. described by Bakke, are considered conspecific,L. melospizaeMcIntosh sp. inquirenda. The tendencies for larval differences to be correlated with geographical subregions were judged to be no more than intraspecific variation within a brown‐banded sporocyst complex. Different characteristics of both larval and adult stages are described in more detail and

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00521.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Anchistrocephalus microcephalus(Rudolphi, 1819) is redescribed from the intestine ofMola mola. Contrary to earlier descriptions, specimens may appear to have an unarmed scolex or a scolex with a few hooks only, and some proglottids exhibit duplicate genitalia. The specific diagnosis has been amended to take account of this greater range of variation. As a consequence,AmphigonophorusMendes, 1944 is rejected andAmphigonophorus carvalhoibecomes a synonym ofAnchistrocephalus microcephalus.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00522.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The morphology ofParanemertes sanjuanensissp.n., a new monostiliferous hoplonemertean from San Juan Island, Washington, is described. As in other members of the genus,P. sanjuanensishas numerous eyespots, a proboscis sheath that extends one‐half to two‐thirds the length of the body, well‐developed cephalic and subepidermal glands, and two distinct layers of longitudinal muscles in the body wall of the cerebral region. A precerebral septum is absent, as only fibers from the inner longitudinal layer extend into the proboscis. The cerebral sense organs are well developed and lie just anterior to the brain. The esophagus opens into the rhynchodaeum and leads posteriad, into a highly folded stomach. The intestinal caecum is short and lacks anteriorly directed pouches. Gravid females have numerous ovaries in the posterior two‐thirds of their bodies. The proboscis is relatively large and contains an average of 5 reserve stylet sacs, each of which contains 2 to 3 stylets. The stylets are stout and have prominent, helically‐arrange

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00523.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Ikosipodus carolensisgen. et sp.n. from shallow subtidal sands off the coast of North Carolina is described. The species shows conspicuous neotenic features. The sexes are separate and dimorphic. The juveniles resemble the adults greatly. A seminal receptacle in the male, of which the fine structure was investigated, is the first proof of direct sperm transmission in the Dorvilleidae. The new form has been classified into a tentative phylogenetic dendrogram of the dorvilleid genera

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00524.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

According to Bennike (1943) the leech fauna in Lake Esrom, Denmark, includes two types ofGlossiphonia complanata(L.), namelyG. complanata typicaBennike, 1943 andG. complanata concolor(Apáthy, 1888). The results of the present investigation, which were based on material collected in 1975, 1976, and 1980, strongly indicated that we are dealing with two species in Lake Esrom, namelyGlossiphonia complanata(L.) andG. (Clepsine) concolor(Apáthy). The two species have a rather similar life history, butG. complanatais on average larger thanG. concolor. Differences in reproduction included size of eggs and timing of breeding, but the number of offspring seemed to be similar. Tank experiments revealed that all offspring ofG. complanatahad a conspecific parent, and likewise forG. concolor. The general appearance of the two species is significantly different, and the average ratio of body width to body height (W/H ratio) was ca. 30% higher for preserved individuals ofG. complanatathan forG. concolor. The ecological distribution of the two types, and the reliability of pigmentation as a diagnostical tool in leech systematics are discussed. Characters used for the identification of the species are include

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00525.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Pelagic juvenile pipefishes, representing three genera previously unrecorded from the eastern Atlantic region, are reported from collections of the 1928–30 DANA expedition.Cosmocampus retropinnissp. n., with dorsal‐fin origin on tail and 6.75–8.0 subdorsal rings (S Morocco to Gambia),Minyichthys sentussp. n., with patches of spinules on snout and 42 tail rings (W Mediterranean and Atlantic Ocean off N Morocco and Canary Is.), andAmphelikturussp. (off Sierra Leone) are described and figured. The subgenusMinyichthysHerald and Randall is rediagnosed as a genus characterized, in part, by an 8‐rayed caudal fin. A key is provided to the nine genera of Syngnathidae known from the eastern Atlantic

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00526.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Spatial organization of collagenous fibrils in the basal plate of elasmoid scales has been studied in 36 species among 24 teleost families which include the whole order. Angle measurements of the various fibrillary directions were performed on fracture surfaces in frozen scales observed with the scanning electron microscope. The organization of the basal plate is arrayed in three basic patterns. The most remarkable one, found in the more “primitive” families, is a double twisted plywood with a left‐handed rotation of the fibrillary directions. The remaining two are an orthogonal plywood, more or less regular, and an “intermediate” plywood, both found among the more “advanced” families. However, an orthogonal plywood is also observed in some “primitive” families, for example in Clupeidae and Salmonidae. We tentatively interpret the left‐handed double twisted plywood of the lower teleosteans and of Amiidae as a synapomorphy in relation to the primitive condition of an actinopterygian lineage. On the other hand, within the teleosts, we would consider that the double twisted plywood is a plesiomorphic condition and that the orthogonal plywood is an apomorphy among the “advanc

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1982.tb00527.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY