Their absence attenuated the flicking rate of the antennules
. but in a chemical stimulus-independent manner.
They are located on the lateral (outer) flagella of the antennules
(Grunert & Ache 1988, Steullet et al.
During settlement, the cyprid uses the antennules
to walk over the substratum in search of an attachment site, until it finally and irreversibly cements itself and commences metamorphosis (Fig.
Geniculation in both antennules
is common in cyclopoid families, such as Fratiidae, Cyclopidae and Cyclopinidae (Boxshall and Halsey, 2004), but not in calanoids.
Rudiments of the antennules
and biramous antennae are clearly defined, the latter with a medial epipodite.
The olfactory antennules
of aquatic crustaceans are useful systems for studying the physical process of odor capture, because antennules
protrude into the water where we can measure their interactions with the fluid environment.
Manganese accumulation by the antennule
of the Norway lobster Nephrops norvegicus (L.) as biomarker of hypoxic events.
The bases of the antennules
were sealed within the olfactometer with petroleum jelly to isolate them from the recording chamber.
In juvenile animals the principal canal leads into the attachment disk of the vestigial antennules
, where the cement is extruded through several pores.
Crustaceans possess an impressive diversity of setae on the surface of their exoskeletons, with a particularly large number located on the antennules
, the first pair of antennae.
Crayfish detect odors from distant sources with their antennules
, located medially to the antennae.
In either case, the chemical cues are perceived by chemosensory structures (aesthetasc sensilla) that are concentrated on the outer flagella of the first antennules
of the crabs (Hallberg & Skog 2011, Schmidt & Mellon 2011).