It occurs most commonly from October through June, with greatest abundance in the Fall. The heaviest period of larval settlement in this species is in Fall, from October through January, though new colonies continue to settle through June. Globular ovicells are present. These are hyperstomial and have rough calcification around the outside, with a smoother, porous central area. The central area may become secondarily calcified.
Embryos are a red-orange color.
H. verrilli is eurythermal , with its period of heaviest reproduction occurring in cooler months. H. verrilli was typically found encrusting wood, shell and other hard substrata . Seagrasses as well as floating macroalgae , provide support for bryozoan colonies. In turn, bryozoans provide habitat for many species of juvenile fishes and their invertebrate prey such as polychaete worms, amphipods and copepods. Bryozoans are ecologically important in the Indian River Lagoon due to their feeding method.