The Myogenic Automatism of the Systemic Heart of Octopus Vulgaris (cephalopoda: Coleoidea): Evidence for Localized Stretch Sensitivity and Pacing Activity
نویسنده
چکیده
The localization of the stretch sensitivity and myogenic automatism in the systemic heart of Octopus vulgaris has been studied on an isolated preparation in which the ventricle was zoned by ligatures. Each region has been submitted to two different levels of internal hydrostatic pressure (1 and 2 kPa). Only the two atrio-ventricular regions were able to contract regularly when submitted to internal pressure, with a frequency dependent from the pressure value, while the ventricle-aortic region was insensitive to the stretching by internal pressure. This result supports the hypothesis that the automatism in this heart is localized. Electrocardiogram recordings from different areas of an isolated and perfused preparation of the systemic heart ventricle are also reported, which suggest that the electrical activity of the ventricle originates in two narrow areas near the atrio-ventricular valves.
منابع مشابه
A new Cenomanian (Late Cretaceous) coleoid (Cephalopoda) from Hâdjoula, Lebanon
The fossil record of cuttlefish, squid and octopus has received relatively little attention. Among malacologists, the opinion is widespread that these mainly softbodied coleoids have a poor fossil record. However, thanks to Konservat-Lagerst tten such as the Early Jurassic Posidonian Shales of Holzmaden (Germany), the Middle Jurassic La-Voulte-sur-Rh ne (France) and the Late Jurassic Limestones...
متن کاملPrey-handling behaviour of Octopus vulgaris (Mollusca, Cephalopoda) on Bivalve preys.
This study examines the ability of Octopus vulgaris to prey on bivalve molluscs showing that octopuses exhibited the same behavioural pattern irrespective of the prey species. When the initial pulling method did not result efficient octopuses skipped to drilling accompanied by an increase in the handling time. A complete behavioural repertoire of O. vulgaris in handling bivalve preys is also gi...
متن کاملPhylogeographical Analysis of Octopus Vulgaris (mollusca, Cephalopoda) in the Mediterranean: Insights from the Coi Mitochondrial Gene
This work reports a genetic data of Octopus vulgaris, marine species of high commercial value, from nineteen localities of Atlantic, Mediterranean and the Adriatic regions. We used mitochondrial DNA cytochrome c oxidase subunit I (COI) gene to investigate the genetic structure of common octopus. Our results indicated a significant genetic structuring in the study area (Phi = 0.136, P <0.001) an...
متن کاملShort Communication Contractile Performance of Cephalopod Hearts under Anoxic Conditions
The cephalopod circulatory system includes an efferent systemic ventricle and two afferent branchial hearts. Branchial hearts lack coronary arteries and thus must be nourished by only venous blood. During routine metabolism in normoxic water, oxygen availability to branchial hearts is only a small percentage of that to the systemic heart; during hypoxic excursions the venous oxygen content may,...
متن کاملDiet Composition and Variability of Wild Octopus vulgaris and Alloteuthis media (Cephalopoda) Paralarvae: a Metagenomic Approach
The high mortality of cephalopod early stages is the main bottleneck to grow them from paralarvae to adults in culture conditions, probably because the inadequacy of the diet that results in malnutrition. Since visual analysis of digestive tract contents of paralarvae provides little evidence of diet composition, the use of molecular tools, particularly next generation sequencing (NGS) platform...
متن کامل