Use of microspheres, fresh and microbound diets to ascertain dietary path, component size, and digestive gland functioning in phyllosoma of the spiny lobster Panulirus ornatus

The ability of Panulirus ornatus phyllosoma to capture, feed and process diets of different texture and particle size were studied during developmental stages I, III and V. Diets were captured using the spines and dactyl on the second and third pereiopods and brought to the oral cavity assisted by the second and third maxillapeds. Optimal capture was obtained when diets were a gelatinous-muscular consistency, and hard particles were caught when embedded in a muscular carrier. A range of food textures, from gelatinous to hard, were able to be masticated in the oral cavity by stage V phyllosoma. Masticated particles were filtered by phyllosoma through spines and hairs in the proventriculum, during stages I–II, and a filter press in stages III–V. Maximum particle size passing into the midgut gland for digestion was 7, 3 and 0.5 µm in stage I, III and V phyllosoma, respectively. B cells were prominent in the proximal ends of the caece of stage V phyllosoma and were visible in live animals under light microscopy.