Laboratory observations on spawning and embryonic development of a blue-ringed octopus

A female blue-ringed octopus, Hapalochlaena sp. (probably lunulata), was maintained in an aqarium for nearly 3 months, during which time it spawned and cared for the eggs until hatching. The young are planktonic. Embryonic development does not differ markedly from that observed in other octopods, uniting certain features of the development of Octopus vulgaris and Eledone cirrosa. In terms of reproductive biology and development, the species differs from the lesser blue-ringed octopus Hapalochlaena maculosa in its mode of spawning, egg size and mode of life of its young. These differences correspond to conditions recorded for Octopus spp. and Eledone spp

Ocean acidification and temperature rise: effects on calcification during early development of the cuttlefish Sepia officinalis

This study investigated the effects of seawater pH (i.e., 8.10, 7.85 and 7.60) and temperature (16 and 19 °C) on (a) the abiotic conditions in the fluid surrounding the embryo (viz. the perivitelline fluid), (b) growth, development and (c) cuttlebone calcification of embryonic and juvenile stages of the cephalopod Sepia officinalis. Egg swelling increased in response to acidification or warming, leading to an increase in egg surface while the interactive effects suggested a limited plasticity of the swelling modulation. Embryos experienced elevated pCO2 conditions in the perivitelline fluid (>3-fold higher pCO2 than that of ambient seawater), rendering the medium under-saturated even under ambient conditions. The growth of both embryos and juveniles was unaffected by pH, whereas 45Ca incorporation in cuttlebone increased significantly with decreasing pH at both temperatures. This phenomenon of hypercalcification is limited to only a number of animals but does not guarantee functional performance and calls for better mechanistic understanding of calcification processes

Congenital malformation of the systemic heart of Sepia officinalis l.: morphological, phylogenetic and ecotoxicological aspects

Numerous preparations of the circulatory system of Sepia officinalis L. caught from the Bay of Arcachon (Atlantic Coast of France) in 1989 and 1996 showed an obvious congenital malformation of the systemic heart complex. The malformation consisted of a cord- or truncus-like structure at the left cranio-apical ventricle. It is interpreted as an atypical second root of the cephalic aorta reflecting an originally paired anlage of the heart in ancestral cephalopods. In considering possible causes of this atavistic abnormality, the high tributyltin (TBT) contamination recorded in the Bay at the time should not be overlooked

Das Eingraben in Sand bei Sepiola und Sepietta (Mollusca, Cephalopoda)

Volume: 77Start Page: 536End Page: 54

Gut development in cephalopods: a correction

Volume: 85Start Page: 379End Page: 38