摘要:

AbstractA perusal of the literature on copepod cuticles has been made, and results of the investigation of six species made by the author are included in this review.The integument of copepods is of the arthropod type. Pore canals and other structures traversing the cuticle, common in most arthropods, are not always present in free‐living and some parasitic copepods.In parasitic forms, with advanced morphological changes, the cuticle is generally very thin and the epicuticle in many species forms external microvilli‐like structures. In the copepods hitherto investigated the epicuticle is probably the sole layer present in the cuticle.Some copepods show specialized regions of the cuticular surface, the function of which still remains obscure. Integumental organs and integumental structures are numerous and variable. The association of bacteria with the cuticle has been observed in many species.The structure of the integument of parasitic species lacking an alimentary tube and in close contact with the host tissue or hemocoelic cavity supports the idea that the integument could be the obligatory site of nutrient uptake. In spite of the relatively few species of copepods that have been investigated, a remarkable variation of cuticular fine structure has been revea

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1986.tb00857.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAntisera raised against salmon insulin and bovine insulin were used to assess the distribution of insulin‐like immunoreactive neurons in the neural ganglion ofCiona intestinalis.Cell bodies of two sizes were found in cortical and medullary positions, together with an extensive network of immunoreactive fibres. These observations indicate that an insulin‐like material is an important component of the central nervous system inCionaand gives weight to the hypothesis that protochordates utilize insulin‐like factors as neurotransmitters or modulators, as do their invertebrate ance

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1986.tb00858.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe nervous system (NS) of the coracidium and procercoid larval stages of the pseudophyllidean cestodeDiphyllobothrium dendriticumwas examined by whole mount immunocytochemistry and electron microscopy. Antisera against the bioamine serotonin and the molluscan cardioexcitatory peptide FMRF‐amide gave a positive immunoreaction in the NS of the procercoid. Ultrastructurally, three types of nervous elements were discerned. Ultrastructural evidence of both aminergic and peptidergic neurons in the coracidium is provided. The NS of these early larval stages is simply organized. The serotonergic part of the NS shows a beginning centralization in the procercoid, while the peptidergic neurons are more peripherally distribute

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1986.tb00859.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThePerkinsianaacrosome is elongated, pointed and tapering, strengthened anteriorly by cortical rings of longitudinally running units. ThePseudopotamillaacrosome is cap‐like and its apical region contains a laminar body with two electron densities, the laminae crossed by occasional lines of dislocation, as in a crystal. These apparently solid regions are closely followed by peripherally situated lucent zones. The zone inPseudopotamillacontains tubules, which are very like those inSabellasperm, except that they lack connections with the acrosome base. Both species are probably broadcast spawners and have nuclei, mitochondria, centrioles and flagella of the primitive type. This may, however, be a secondary reversion through neoten

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1986.tb00860.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractHeart, pericardium and glomerular vessel ofCephalodiscus gracilishave been studied with the electron microscope. The lumen of the heart is lined by a basal lamina and an associated epithelium, composed of myoepithelial cells with well developed thin and thick myofilaments. The heart is located in the pericardial cavity, which is deliminated by the pericardium. The latter is composed of two flat layers of myoepithelia with fused basal laminae. The outer layer of the pericardium is the protocoelomic lining, and the inner layer is the ‘parietal’ pericardial epithelium. The myoepithelium forming the heart wall can be considered to represent the ‘visceral’ pericardial epithelium. The spacious glomerular vessel is lined by a basal lamina, on which typical podocytes rest. These cells indicate that ultrafiltration takes place through the wall of the glomerular vessel. The lumen of the vessel contains fine granular material (presumably precipitated blood proteins), fibrils with a faint cross striation, suggesting that they represent collagen, and stellate cells, which in part line the vessel. Since ultrafiltration requires hydrostatic pressure, it is inferred that the blood flow is from the dorsal region then through the heart and into the glomerular

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1986.tb00861.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe tentacles of the pterobranchCephalodiscus, a hemisessile ciliary feeder, originate from the lateral aspects of the arms and are covered by an innervated epithelium, the majority of its cells bearing microvilli. Each side of a tentacle has two rows of ciliated cells and additional glandular cells. The coelomic spaces in the tentacles are lined by cross‐striated myoepithelial cells, allowing rapid movements of the tentacles. One, possibly two, blood vessels accompany the coelomic canal. On their outer sides the arms are covered by a simple ciliated epithelium with intra‐epithelial nerve fibres; the inner side is covered by vacuolar cells. On both sides different types of exocrine cells occur. The collar canals of the mesocoel are of complicated structure. Ventrally their epithelium is pseudostratified and ciliated; dorsally it is lower and forms a fold with specialized cross‐striated myoepithelial cells of the coelomic lining.Arms, tentacles, associated coelomic spaces and the collar canal of the mesocoel are considered to be functionally interrelated. It is assumed that rapid regulation of the pore width is possible and even necessary when the tentacular apparatus is retracted, which presumably leads to an increase of hydrostatic pressure in the c

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1986.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY