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Hydractinia echinata (Hydrozoa) - Ablaichen, Embryonalentwicklung, Metamorphose


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Formal Metadata

Title Hydractinia echinata (Hydrozoa) - Ablaichen, Embryonalentwicklung, Metamorphose
Alternative Title Hydractinia echinata (Hydrozoa) - Spawning, Embryonic Development, Metamorphosis
Author Müller, Werner
License No Open Access License:
German copyright law applies. This film may be used for your own use but it may not be distributed via the internet or passed on to external parties.
DOI 10.3203/IWF/E-2080
IWF Signature E 2080
Publisher IWF (Göttingen)
Release Date 1975
Language Silent film
Producer IWF
Production Year 1973

Content Metadata

Subject Area Life Sciences
Abstract Übersicht über weiblichen Stock und männlichen Geschlechtspolyp. Abgabe von Eiern und Spermien. Embryonalentwicklung: total-äquale und pseudospiralige Furchung. Entwicklung der Morula zur Planula. Fortbewegung der Planula. Metamorphose zum Primärpolypen aus verschiedenen Perspektiven. Auswachsen von Stolonen und Sekundärpolypen. Elongationsrhythmik.
Hydractinia echinata represents one of the few hydroids the embryogenesis and metamorphosis of which can easily be induced and observed. The sexual products mature within the gonophores of specialized gonozooids and are shed into the open water in the morning after illumination. Cleavage is toal, equal, and pseudospiral, and gives rise to morulae which expand to ciliated planulae. The metamorphosis of the planulae into primary polyps can be induced by application of certain bacteria or of a Cs+-pulse. The spindle-shaped larva shortens by muscular contraction and acquires a discshaped appearance. The apical part of the convex disc emerges to form the hydrant, whereas the basal part growths stolons.
Keywords Stachelpolyp
Metamorphose / Coelenterata
Hydractinia echinata
Fortpflanzung, geschlechtliche / Coelenterata
Eiablage / Coelenterata
egg deposition / Coelenterata
oviposition / Coelenterata
metamorphosis / Coelenterata
reproduction, sexual / Coelenterata
snail fur

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