The defensive withdrawal reflex of the mantle organs of Aplysia californica exhibits a variety of forms of both nonassociative and associative learning, which can exist in both short- and long-term forms. In addition, the reflex can be readily elicited and quantified as soon as the effector organs (siphon and gill) emerge at their respective developmental stages. Thus, this reflex system provid...

The siphon indices, branching of setae 5-C and 6-C, lengths of 5-C compared to the lengths of 6-C, length of the most proximal seta 1-S compared to the siphon length, and the occurrence of a paler abdominal segment IV were compared among Culex apicalis, Cx. boharti and Cx. territans larvae. These characters in Cx. territans were found to be much more variable than previously recognized, and oft...