The life history and ecology of the littoral centipede Strigamia maritima (Leach).
Abstract
The investigation, on the littoral centipede Strigamia
maritima (Leach), was carried out between 1956 and 1959 largely at Cuckmere Haven, Suesex. The main habitat studied
was a shingle bank the structure and environmental conditions
of which are described.
A description of the eggs and young stages of Strigamia
is given and it is shown how five post larval instars may
be distinguished by using head width, average number of
coxal glands and structure of the receptaculum seminis in
females, and head width and the chaetotaxy of the genital
sternite in males. An account of the structure of the
reproductive organs and the development of the gametes, and
of the succession, moulting, growth rates and length of
life and fecundity of the post larval instars is given, and the occurrence of a type of neoteny in the species is
discussed. It is shown that S. maritima is able to withstand long
periods of immersion in sea water by virtue of the faut
that it can utilise oxygen in solution. Tho animal is,
however, slowly desiccated under these conditions and it is
suggested that this is the reason for the observed migration
out of submerged areas and the confinement of the majority
of Strigamia populations to the top of the 1ittoral zone. It is further suggested that the population at Port Erin,
Isle of Man, which occurs at mid-tide level, may be a
physiologically different form. The animal is shown to
migrate to the top of the beach to breed and moult and
it is suggested that it is only because the top of the beach 1s not covered by spring tides during the summer months that the centipede can remain in the littoral zone
throughout the year.
Another centipede Hydroschendyla submarina was
studied at Plymouth and found to be far better adapted
to a littoral life than Strigamia since it lays impermeable
eggs and breeds and moults well below the high water mark.
Field and laboratory experiments on the feeding habits
of Strigamia are reported, and the animal is shown to prey
on a variety of invertebrates. It is possible that small
specimens of the centipede are preyed on by some littoral
beetles.
The animal almost completely lacks internal parasites
but most individuals bear hypopi of a tyroglyphid mite;
these, however, are probably harmless.
Authors
Lewis, John Gordon ElkanCollections
- Theses [3826]