image Copyright 1997 Regina Wetzer
This is a scanning electron micrograph (SEM) of an adult diapausing Heteropsysllus nunni. This adult is about 1mm in length. H. nunni lives in shallow, sandy, meiofaunal marine habitats off the South Carolina coast. I have broken away a portion of the cyst to expose the copepod. Its head and thorax are in the center of the image, the abdomen wraps upwards and to the left.
image Copyright 1997 Regina Wetzer
A variety of survival strategies for coping with unfavorable environmental conditions have evolved among the Arthropoda. Among crustaceans those taxa inhabiting inland bodies of water, especially those habitats that occasionally freeze or dry, are more likely to possess a diapausing stage than are taxa living in the ocean. However, diapause occurs not only in numerous freshwater harpacticoid copepods, but also in at least two marine species. [See: Coull, B. C. and J. Grant 1981. Encystment discovered in a marine copepod. Science 212: 342-344.]
Harpacticoids are abundant and speciose. I am interested in the phylogenetic history of harpacticoids and the evolution of diapause in this group.
To learn more about meiofauna, visit the Coull Meiofauna Lab.