Spine Formation as a Hatching Tool in Euprymna scolopes (Mollusca, Cephalopoda, Sepiolidae)

Autor(en)
Janek Von Byern, Alexandra Kerbl, Marie-Therese Nödl, Giambattista Bello, Yannick Städler, Jürg Schönenberger, Norbert Cyran
Abstrakt

The hatching of an embryo from its egg is a crucial point in its development. This is the moment that decides whether the animal will be able to emerge and survive or whether it will remain trapped and die. Cephalopods usually produce enzymes in a system of glands known as the Hoyle organ, which weakens the chorion and enables hatching. In addition to this chemical approach, four cephalopod genera develop a terminal spine to further support the hatching process.

The presence of such a spine has been mentioned for the well-known cephalopod species Euprymna scolopes. However, little is known about either its structure or its cellular details. Our present results indicate that the spine consists purely of musculature, and no intermediate connective tissue was observed. No nerves were detected within the spine, although nerve fibers are present within the surrounding epithelium and dermal muscle layer, indicating that the spine stretching is controlled by this dermal musculature.

Our data show that the spine of Euprymna is similar in its composition to those of the other three cephalopod genera in which a spine has evolved. However, we found morphological differences in the spine tip and in a collagenous layer located between the spine and the normal epithelium. It remains unclear why two completely different but synergetic systems for hatching, the glandular Hoyle organ and a spine, exist in some, but not all, cephalopod genera.

Organisation(en)
Department für Botanik und Biodiversitätsforschung, Core Facility für Cell Imaging und Ultrastrukturforschung
Externe Organisation(en)
Ludwig Boltzmann Institut für Experimentelle und Klinische Traumatologie, University of Copenhagen
Journal
Malacologia
Band
59
Seiten
231-238
ISSN
0076-2997
DOI
https://doi.org/10.4002/040.059.0204
Publikationsdatum
2016
Peer-reviewed
Ja
ÖFOS 2012
106042 Systematische Botanik, 106008 Botanik, 106012 Evolutionsforschung
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/spine-formation-as-a-hatching-tool-in-euprymna-scolopes-mollusca-cephalopoda-sepiolidae(ffbeedaa-122e-4a66-8315-19ebef696e35).html