Innate landward orientation in the littoral isopod Tylos europaeus

Solar orientation experiments have shown that laboratory-born (inexpert) young of the littoral isopod Tylos europaeus are capable of using the sun compass to assume an escape direction corresponding to the Y axis of their mother's home shore. As in sandhoppers, the escape direction and capacity for solar orientation appear to be innate. The hypothesis whereby the direction of the sealand axis is innate in littoral arthropods with direct development, inhabiting rectilinear coastlines and having a limited vagility along the X axis is discussed.