Research Training Program

Tentacular morphology, or shape and structure of tentacles, has long been used in species level taxonomy and other research on cephalopods, the advanced group of marine mollusks that are active marine predators including octopuses, cuttlefishes, nautiluses and squids. However, taxonomy of this type has primarily focused on adult forms, giving little regard to paralarval and juvenile forms and their development into the more commonly researched more mature forms. In this research project, the morphological development of the tentacular club of Ctenopteryx sicula, or comb-fin squid, a pelagic, ooegopsid squid found throughout the Atlantic Ocean, was assessed in its paralarval form by way of Scanning Electron Microscope (SEM) analysis of tentacles collected from specimens ranging from 2.9mm to 8.3mm DML, with DML being dorsal-mantle length, a cephalopod's sizing measure from the anterior to posterior end of the mantle. Analysis of the tentacular club series indicated distal (terminal) elongation of the distinctively circular sucker pad of the 2.9mm Ctenopteryx, with the youngest and least developed suckers residing at the distal tip, which acts as the developmental meristem of the club. Further analysis also served to prove character permanence in the original suckers on the pad of 2.9mm Ctenopteryx, which do not differentiate nor grow further as the paralarvae develops and are quickly outgrown by the secondarily developed distal suckers, which become increasingly differentiated with greater distance from the distal tip. This research contributed significantly to the extremely limited understanding of cephalopod early life histories and therefore to the overall understanding of and appreciation for the oceans and marine ecosystems as a whole.