Meeting Abstract

6.1  Sunday, Jan. 4  Aplysina Red Band Syndrome: An emerging infectious disease of coral reef sponges THACKER, R.W.**; GOCHFELD, D.J.; OLSON, J.B.; Univ. of Alabama at Birmingham; Univ. of Mississippi; Univ. of Alabama thacker@uab.edu

Disease is often implicated as a major factor contributing to continuing declines in the health of Caribbean coral reef communities. Most studies of coral reef diseases have focused on scleractinian corals, whereas sponge diseases have been less frequently documented. We are currently investigating Aplysina Red Band Syndrome (ARBS), which affects Caribbean rope sponges. Visible signs of disease presence include one or more rust-colored leading edges, with a trailing area of necrotic tissue, such that the lesion forms a contiguous band around a portion of or the entire sponge. Microscopic examination of the leading edge of the lesion indicates that filamentous cyanobacteria are responsible for its coloration. Although the presence of this distinctive coloration is used to characterize the diseased state, it is not yet known whether this cyanobacterium is the causative agent of this disease. ARBS is present throughout the Caribbean; surveys in Belize and the Bahamas revealed that up to 10% of Aplysina cauliformis individuals are infected. In laboratory aquaria, ARBS lesions expanded at a rate of up to 1 mm per day. Transmission studies in the lab and field demonstrated that contact with an active lesion’s leading edge was sufficient to spread ARBS to a healthy sponge, suggesting that the etiologic agent is contagious. Population studies indicate clumping of diseased individuals on the reef, but the presence of affected individuals in isolation suggests that waterborne transmission is also likely. Studies to elucidate the etiologic agent of ARBS are ongoing. Sponges are an essential component of coral reef communities and emerging sponge diseases have the potential to impact benthic diversity and community structure on coral reefs.