Mouthpart and foregut structure indicates that
Jasus edwardsii phyllosomas ingest soft fleshy foods such
as gelatinous zooplankton. Mouthpart morphology changes little during larval
development, indicating that ingestive capabilities and external mastication
are well developed from an early age. However, the density and complexity of
setation and robustness of individual mouthparts increases with age,
suggesting a greater capacity to ingest larger prey during development. The
foregut consists of a single chamber with a number of well-developed grooves,
ridges, and setae but lacking a gastric mill. The primary role of the foregut
is mixing, sorting, and filtering particles, preground by the mouthparts.
Phyllosomas have been divided into early (stage I–III), mid
(IV–V), and late (VI–X) stages based on the development of the
filter press and main brushes. Increasing robustness of setation and
complexity of the foregut suggest that the texture of prey becomes more
muscular (fibrous) with larval development. The results presented here suggest
that early-stage phyllosoma would benefit from a diet comprising soft
gelatinous items, whereas late-stage phyllosomas are better prepared to deal
with larger, fleshy prey. The changes in structural characteristics with age
should also serve as a guide in the development of formulated diets.
Ontogeny of phototactic behavior in phyllosoma larvae of the Japanese spiny lobster Panulirus japonicus
