Mouthpart and foregut ontogeny in phyllosoma larvae of the spiny lobster Jasus edwardsii (Decapoda: Palinuridae)

Abstract

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.

DNA identification of the phyllosoma diet ofJasus edwardsiiandScyllarussp. Z

“…Z stage IX. These late stage phyllosomas are thought to have the morphological and enzymatic capabilities to capture, consume and digest fleshy prey items such as fish larvae (Macmillan et al 1997;Johnston & Ritar 2001;Cox & Johnston 2003b;Johnston et al 2004). Phyllosomas are voracious predators in culture, actively capturing their prey, including fish larvae (Macmillan et al 1997;Cox & Bruce 2003;Cox & Johnston 2003a;Kittaka et al 2005;Jeffs 2007;Saunders et al 2012).…”

“…The ability of phyllosomas to handle and digest fleshier prey appears to increase with larval size and development (Cox & Johnston 2003a, b). Enzyme profiles, lipid tracer studies and aquaculture feeding trials all show that phyllosomas are capable of digesting a variety of prey (Johnston & Ritar 2001;Johnston et al 2004;Jeffs 2007). This previous research gives us a starting point for molecular techniques which offer significant potential for reliably identifying the natural diet of phyllosoma.…”

A Global Review of Spiny Lobster Aquaculture

“…Linton et al (2003) documented Artemia rearing techniques. A number of studies of the mouthparts, feeding behaviour and digestion of several species including J. edwardsii and S. verreauxi have been conducted to understand the feeding behaviour and assimilation processes (Johnston & Ritar 2001 ;Nelson et al 2002a ;Cox & Johnston 2003aJohnston et al 2005 ;Cox et al 2008 ). Other studies have looked at digestive enzyme profi les (Johnston et al 2004a,b ).…”

“…The morphology of the mouthparts and the digestive tract of phyllosoma larvae are also being investigated to help understand dietary requirements (Johnston 2000(Johnston , 2003Johnston et al 2003 ;Johnston 2007 ). Another area of research is examining the manipulation of the moulting times using hormones (Hall et al 2001 ).…”

Developmental changes in foregut functioning of packhorse lobster, Jasus (Sagmariasus) verreauxi (Decapoda:Palinuridae), phyllosoma larvae

“…The structural similarities between the foregut of J. edwardsii and J. verreauxi (Johnston and Ritar 2001) suggest a similar digestive mechanism; however, J. verreauxi appears to have more developed internal mastication and filtration in early instars. In instars 1-3 of J. verreauxi phyllosomas, the ventralmost lateral setae in the anterior foregut are larger than those of early-instar J. edwardsii, which are all of a similar size (Johnston and Ritar 2001).…”