The tendency to form aggregations is one of the Gyrinidae’s most peculiar attributes. These aggregations can be composed of several species and sometimes multiple genera.  The purpose of this study was to survey the Gyrinidae of the Texas Primitive Big Thicket and record their aggregating behavior, including the composition of their aggregations and their habitat preference. Gyrinids were collected from lotic and lentic sites in the Texas Big Thicket, where species frequently exhibited aggregation.

Results/Conclusions

Aggregations consisted of two or more species, and some aggregations had species representing up to three genera: Dineutus MacLeay, Gyretes Brullé and Gyrinus Müller. Habitat preferences for these beetles was also recorded.  In the Big Thicket region of east Texas, gyrinids are most commonly found in species aggregations and were rarely collected as single species groups.