Hatching glands in cephalopods – A comparative study

摘要: Abstract Hatching of embryos from their eggs involves either mechanical and/or chemical support. In particular enzymes are widely used in the animal kingdom to weaken egg layers and facilitate embryo's escape. Although numerous morphological biochemical studies exist on hatching glands invertebrates (such as sea urchins, ascidians, insects) vertebrates (teleosts, amphibians, mammals), little is known about morphology (Hoyle organs) cephalopod hatchlings. this study, internal gland structure external appearance Hoyle organ compared among several species (Idiosepius pygmaeus; Euprymna scolopes; Sepia officinalis; Loligo gahi; Sepioteuthis lessoniana; Architeuthis sp.; Octopus vulgaris; Tremoctopus gracilis; Argonauta hians). almost all cases glandular system restricted posterior part dorsal mantle surface. Only lack a specific body region animals apparently use other mechanisms penetrate layers. decapod (Idiosepius; Euprymna; Sepia; Loligo; Sepioteuthis; Architeuthis) well only one cell type present organ, which synthesizes granular material. The secretory droplets more or less uniform electron density Idiosepius, but exhibit translucent inclusions decapods. time development, first synthesis products later degeneration after vary between species. study contributes our knowledge systems cephalopods allows comparison with structures vertebrates.