Research Training Program

Smithsonian Institution
National Museum of Natural History

PROJECT SUMMARY
1997


Luisa I. Falcon
Universidad Nacional Autonoma de Mexico,
Mexico D.F.
Michael Vecchione, Ph.D.
Clyde F.E. Roper, Ph.D.
Supervising Scientists
Department of Invertebrate Zoology
Division of Mollusks
"Interning at the NMNH helped me realize the importance of pursuing an understanding of organismal systematics in order to better comprehend the natural world."

The Squid Family Gonatidae (Mollusca: Cephalopoda) from the
Amsterdam Mid-North Atlantic Plankton Expeditions

ABSTRACT
The members of the squid family Gonatidae from the North Atlantic have been separated in two species, Gonatus fabricii (Lichtenstein, 1818) in the Arctic and Gonatus steenstrupi Kristensen, 1981 in boreal waters. During this research, specimens belonging to the genus Gonatus collected during the Amsterdam Mid-North Atlantic Plankton Expeditions were analyzed. Identification of the two species reported for the North Atlantic was done, which attributes a new distribution for the members of this family farther south than expected. The identification of specific characters for each species helped in the separation of their paralarvae which is important in the study of their early life history stages. The characters used to separate these species were the presence of chromatophores on the ventral side of the head for G. fabricii and the difference between the shape of their funnel organs. The SEM showed more specific differences between the tentacular club, especially on the sucker and hook patterns. A cluster analysis of the 34 variables measured per specimen was done with a Pearson Correlation Coefficient showing with an r = 0.827 the grouping of the specimens in two main clusters which related in 90.73% with the separation done of the population for these two species. The presence of these specimens during spring and summer and absence in fall and winter may suggest some interesting factors of their patterns in distribution.

The Smithsonian Women's Committee granted the funding that made this research experience possible.

Letter of Gratitude