colonies before, during, and after spawning. Male D. cylindrus
(A-C) exhibited inflated tentacles prior to spawning (A; black arrowhead). Mouths were generally not visible. Male colonies released sperm directly into the water column in multiple pulses (B-C). Tentacles were often retracted into the skeleton during and immediately after spawning (C). After males began spawning, female D. cylindrus colonies (D-I) exhibited open mouths (D) and bloated tissues surrounding the mouth (D-F). Eggs were visible prior to release (F; black arrowhead) and were in some cases exposed to ambient seawater through openings in the tissue (F; white arrowhead). Tissue openings were most apparent in a female with heavily-ballooned tentacles shortly after spawning (G). After spawning, females often retracted tentacles into the skeleton (H), however they typically returned to a normal appearance quickly thereafter (I). All scale bars represent approximately 5 mm.