The functional morphology of the putative injecting apparatus of Speleonectes tanumekes (Remipedia)

Abstract

Ever since the first individuals of the class Remipedia were discovered, it has been suggested that these animals are capable of injecting their prey with a venomous or digestive substance using the fang on their maxillules. In this study, we investigate the functional morphology of the putative injecting apparatus of Speleonectes tanumekes. Serial sectioning of specimens shows a pair of well-developed glands in the anterior part of the trunk. Spatial interpretations of serial sections suggest that extensions of the glandular cells collectively continue as ducts that lead to the distal segments of the maxillules where a complex of apodemal muscles, associated with a bulbous reservoir, serve to facilitate injection. Different components of the supposedly injectable substance appear to be separated throughout the apparatus.