ISSN:0373-4137    

DOI:10.1080/11250008609355498

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Zonal orientation in the seashore ecotones particularly that of littoral talitrids depends on several mechanisms, but primarily on the sun compass which compensates for the sun's apparent motion (chronometric solar photomenotaxis). The details of this mechanism have been studied in Mediterranean and North European talitrids, but above all in populations where the astronomic conditions (different apparent motion of the sun in different periods of the year) complicate this dependance on the sun compass. Another aspect of the mechanism is its innate component: laboratory‐born young of both Mediterranean and intertropical populations, when exposed to the sun for the first time, show a statistically significant directional tendency which is ecologically correct and in compliance with the original population. Crosses indicate the presence of a genetic control of behaviour with a continuous circular variability, and of a genetic difference in the escape direction of animal populations capable of chronometric solar photomenotaxis. Chronometric lunar orientation, demonstrated for the first time in the animal kingdom in talitrids, raises interesting problems regarding the mechanism(s) involved and their interference/cooperation with solar orientation. Collateral studies have revealed the extraordinary multiplicity of cues used by talitrids in various conditions. Statistically worthy responses to experimental deviation of the earth's magnetic field have also been obtained both in darkness and sun light. Comparing talitrid orientation to that of other marine or subterrestrial (amphipods, decapods, isopods) crustaceans shows that each species has its own particular set of mechanisms.

ISSN:0373-4137    

DOI:10.1080/11250008609355499

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Role of symbiotic bacteria in the intetsexuality, monogeny and speciation of oniscoid crustaceans

ISSN:0373-4137    

DOI:10.1080/11250008609355500

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This review concerns some new insights from ultrastructural studies combined with fluxes and transepithelial potential measurements on preparations of isolated, perfused gills of the euryhaline Chinese crabEriocheir sinensis.The chinese crabE. sinensisis a strong hyperosmoregulator which has two completely different types of gills. The three anterior pairs of gills have a very thin, respiratory epithelium. The three posterior ones have an epithelium characteristic of salt‐transporting tissues. The permeability to Na+of the anterior gills is relatively high and can be regulated in two different modes: a) a ≪long‐term mode≫ related to long‐term acclimation to sea water or to fresh water b) an ≪immediate mode≫ related to the Na+concentration in the external medium. Both types of modulation result in a decrease in permeability at low external salinity. The permeability to Na+of the posterior gills is always extremely low, whatever the salinity of the medium. The active uptake of salt is only effective in the posterior gills implying independent transport processes for Na+and Cl‐Na+/H+and Cl‐/HCO‐3exchange systems at the apical side of the epithelium. The Na+transport activity can be switched on and off by the Na+level of the blood. Low Na+levels, as in the blood of fresh water crabs, turn the pump activity on whereas high Na+levels, as in the blood of sea water crabs turn the pump off. The pumping system however is not simply turned on and off with acclimation to tresh water or to sea water. The capability for transport is totally lacking in sea water acclimated animals and increases progressively upon acclimation to fresh water. This activity is related to changes in structure of the epithelium and particularly to a large development of an infolding system at the apical side. The applicability of theE. sinensismodel of gill transport to other decapod crustaceans is discussed.

ISSN:0373-4137    

DOI:10.1080/11250008609355501

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Structure, synthesis and degradation of the chitinoproteins of decapod crustaceans

ISSN:0373-4137    

DOI:10.1080/11250008609355502

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The investigation carried out on three Mediterranean population of the genusTigriopusshowed that individuals from the populations Livorno and Rijeka are quite similar from the karyological point of view; on the contrary, the chromosome morphology of the population coming from Trapani is completely different. These results support the hypothesis that the North Tyrrhenian and the North Adriatic strains could represent the extremities of a chain of populations belonging to the same species,Tigriopus fulvus,whereas the South Tyrrhenian population could belong to a different species not yet recorded in this area. Further data collected on the North European species,Tigriopus brevicornis,indicate a great karyological difference between this species and the three Mediterranean populations studied. These results confirm the classification which assigns the populations found respectively in the North European and in the Mediterranean areas to different species.

ISSN:0373-4137    

DOI:10.1080/11250008609355503

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250008609355504

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250008609355505

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250008609355497

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor