Dl. Macmillan et al., FEEDING-ACTIVITY AND THE MORPHOLOGY OF THE DIGESTIVE-TRACT IN STAGE-IPHYLLOSOMA LARVAE OF THE ROCK LOBSTER JASUS-EDWARDSII, Marine and freshwater research, 48(1), 1997, pp. 19-26
First-stage phyllosoma larvae of the rock lobster Jasus edwardsii atta
ched to and fed on larvae of the Tasmanian trumpeter fish, Latris line
ata, when the two were placed together in an aerated, through-circulat
ing sea-water aquarium. Scanning electron micrographs of the mouthpart
s showed adaptations suitable for scraping and cutting soft substrata
Phyllosomas removed from the fish while feeding had pigment particles
from the fish integument throughout their digestive tracts. The behavi
our of these phyllosomas, swimming in a Petri dish, was recorded with
a microscope and video system. The presence of the pigment particles m
ade it possible to see the lumen of the gut diverticulae and parts of
them undergoing regular contractions. Transmission electron micrograph
s of the gut showed that the parts of the gut that contracted in the v
ideo records have well developed muscle bands associated with them. Th
e ultrastructure of the digestive tract is relatively uniform througho
ut and is lined by cells resembling the undifferentiated (E) cells of
other scyllarid and palinurid larvae. Extensive folding of the wall, t
ogether with a brush border on the digestive cells, results in a large
surface area for absorption. There is no grinding or filtering appara
tus in the digestive tract. The behaviour of the phyllosoma, structure
of the mouthparts, and ultrastructure of the digestive tract, suggest
that the first-stage phyllosoma of J. edwardsii is adapted for removi
ng soft tissue from gelatinous organisms and pumping it around the dig
estive tract.