Linking eye morphology to functionality
Meiofaunal animals are small (less than 1mm in size) and live mainly between the sand grains of sediments, often in marine environments. While some of them have developed eyes, others have reduced them and rely on other senses. Members of the two different genera Trilobodrilus and Dinophilus of the family Dinophilidae show a rather similar overall morphology, however, their habitat (in the sediment vs. on the biofilm on its surface) as well as their behaviour (migrations in the sediment, phototaxis, …) differs. While Dinophilus has clearly formed eyes with two sensory cells and one supporting cell, Trilobodrilus does not have eyes, but anterior ciliated sensory organs, which might resemble the eyes of Protodrilidae (another microscopic group of worms). It has not been tested yet what these ciliated sensory organs look like ultrastructurally, how they are connected to the nervous system, and how they influence behaviour and therefore might affect the behaviour of these animals, especially their reaction to light. These morphological and behavioural studies will be supplemented with electrophysiological measurements in light- and dark-exposed animals of the eyes and ciliated sensory organs to further specify the functionality of the respective sensory cells.
The overall objective of this study is to study the morphological basis of behaviour and therefore analyse the detailed ultrastructure and behaviour in several different assays of two related animal species, which differ in their life style and habitat. Based on the outcome of the study, the results will be published in a journal aiming at vision.
|Anvendte metoder:||Microscopy (light microscopy, electron microscopy, confocal laser scanning microscopy), immunohistochemistry, histology, behavioural analyses|
|Keywords:||eyes, nervous system, sensory organ, phototaxis|