摘要:

AbstractPlanktonic larvae of the Athenaria correspond in a number of morphological characteristics to plankto‐trophic thenarian planulae. In edwardsiid planulae there are often, during the later part of the planktonic phase, a well‐developed aboral physa‐“Anlage” and six triangular tentacles. Holotrichous haplonemes are not uncommon in actiniarian planulae. This nemato‐cyst type is, however, limited to the larva stage in the edwardsiid and some thenarian species. The phylogenetical connection between the edwardsiid and the planktotrophic thenarian planulae is stressed The striking morphological resemblances between madreporarian and lecithotrophic planulae of the family Actiniidae indicate a close phylogenetic connection between the two pl

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00743.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractA polystiliferous hoplonemertean,Curranemertes natansgen. et sp.n., is described from Venezuela where it was found on corals in shallow water. It is the third species of reptantic Polystilifera known from the Caribbean Sea. Anatomically the new species shows affinities to the generaPunnettia, Polyschista, andDrepanophorina, but because of differences in the nervous system, cerebral organs, and alimentary tract, a new genus is proposed for it.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00744.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe type locality of the new species is a muddy bottom at a depth of 25 meters in the Gullmarsfjord on the Swedish west coast. On that locality the fauna is recovering from previous sulphite pulp mill pollution. The shape and morphology ofO. maculataconform with most other members of the species. It is distinguished by segmental transverse rows of dark spots. It is a contemporary hermaphrodite with anterior male and posterior female segments. Different from other known species the germ cells are released directly into the water. As a consequence the brood is not protected by the parents.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00745.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractReproduction and larval morphology ofOphryotrocha puerilis, O. labronica, O. nologlandulata, O. hartmanni, andO. bacciare described. All species have been cultivated in the laboratory. The morphology of adults and larvae is uniform, but there is a considerable variation in the shape of the egg masses. The interrelations between members of the genusOphryotrochaare discussed: Gonochoric species have the same type of egg mass and the same chromosome number.O. puerilisis unique as a protandrous hermaphrodite. Among contemporary hermaphrodites with male and female segments, fusiform egg masses with a rigid surface are correlated with one larval type, gelatinous egg masses with another larval type.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00746.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThree‐spined sticklebacks from the northern Baltic proper, caught in 1968 and 1969, were examined with regard to number of plates, body length, head length in relation to body length, and the percental proportions of the formstrachurus, leiurus(=gymnurus), andsemiarmatus.A total number of 1791 specimens were examined. It is shown that the number of asymmetric specimens, regarding the number of plates on the right and left side of the body, is higher than numbers shown earlier, and that there is a significant difference in relative head length between females and males, and, that smaller fish displayed proportionally longer heads than adults.Semiarmatusspecimens accounted for about 80 per cent of the samples and only 2leiurusspecimens were foun

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00747.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe distribution of cholinesterases and non‐specific esterases was investigated by means of histochemical methods. The Résults are tentatively discussed in relation to the ontogeny of the larvae, the control of their behaviour, and the evolution of the cholinergic syst

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1974.tb00748.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY