摘要:

AbstractThe anatomy of the female cypris is very similar to that of cyprids of the Thoracica. There is no development of a preformed kentrogon within the unsettled cypris. Kentrogon formation is completed within 10–20 min after settlement. Elimination of the spent cypris is necessary for successful development. The kentrogon includes a variety of tissues, such as muscles and part of the cement glands. The injection stylet develops in connection with a moult, and it penetrates into the crab gill through the ventral body wall of the kentrogonc.50 h after settlement. Only a single cell, also recognizable in the unsettled cypris, is injected into the host, while the rest of the kentrogon degenerates after invasion. The speed of kentrogen development and much of the kentrogon anatomy can be interpreted as a defense against host crab grooming. The single invasion cell may either be considered as a stem cell or an eg

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1985.tb00645.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractMethyltestosterone (MT) (35 μg/l aquarium water) suppresses steroid production in the testes of sham‐operated fish, as studied enzyme histochemically. This treatment also diminishes the volume of the proximal pars distalis, as well as the area of the gonadotropic (GTH) cell nuclei. Such effects were not found in MT‐treated castrated fish. Castration alone led to a partial degranulation of the GTH‐cells as compared with sham‐operated controls. Extensively dilated granulated endoplasmic reticulum was found in the GTH‐cells of some of the castrated animals and also in GTH‐cells of some castrated fish that had been treated with MT. The possibility of a non‐steroidal feedback mechanism from testes to pituitary is discussed. No effects of the treatments were observed on prolactin cells and on the second basophilic cell type (

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1985.tb00646.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe brain of an adult, female manatee (Trichechus manatus) was prepared for histological examination of the region of the diencephalon and mesencephalon, where the pineal body typically would be located. Careful examination of hematoxylin‐eosin stained, interrupted serial microtomy sections revealed that this animal has a tubular epiphyseal recess apparently lacking organic pineal differentiation. There was no cytological evidence of pinealocytes in the vicinity of the atypical pineal rudimen

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1985.tb00647.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1985.tb00648.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY