Patterns of larval growth, lipid composition and fatty acid deposition during early to mid stages of development in Panulirus ornatus phyllosoma
Wu, X and Smith, GG and Hall, M, Patterns of larval growth, lipid composition and fatty acid deposition during early to mid stages of development in Panulirus ornatus phyllosoma, Aquaculture, 330-333 pp. 63-73. ISSN 0044-8486 (2012) [Refereed Article]
The tropical spiny lobster, Panulirus ornatus, is a commercially important Palinurid marine lobster species of
high market value with wild populations distributed throughout the tropical and sub-tropical Indo-Pacific region.
As wild populations of P. ornatus has been over-exploited, so there is interest in the development of this
lobster aquaculture to meet current and rising market demand for supply. However, a major challenge for
closed-life cycle production of Palinurid lobsters is the development of a commercially viable hatchery technology.
There is minimum knowledge of larval nutrition, and in particular, the lipid requirements. The current
study focused on investigations into the growth pattern and ontogenetic changes of lipid composition
for early–mid stage P. ornatus (stages I–VI) under controlled laboratory conditions. Body wet weight
(WW), dry weight (DW) and total body length (TBL) increased exponentially with the number of stages.
There were large increases in WW, DW and TBL between stages I and VI, with increases of 4092%, 3864%
and 504%, respectively. The greatest increase in DW and WW was noted between stages III to IV while the
greatest specific growth rate (SGR) was noted during stages I to II. The lipid class profile of phyllosoma
was dominated by phospholipids (PL) for all early stages (I–V) despite the high triacylglyceride (TG) content
of Artemia; which was the primary food source. The newly hatched phyllosoma contained higher percentages
of total saturated fatty acids (SFA), 20:5n3 (EPA), 22:6n3 (DHA) and total highly unsaturated fatty acids
(HUFA) compared to that found in all other stages. From stages II to V, the total lipid, lipid class and fatty
acid profile of phyllosoma resembled those of their diet with the exception of 20:4n6 (ARA). The increase
in ARA concentration during phyllosoma development (stages II–V) suggested that mid-stage phyllosoma
(IV and V) had a higher requirement compared to that noted in early-stage (II and III) phyllosoma. It was
noted that early-stage (II and III) phyllosoma preferentially sequestered and accumulated a higher proportion
of EPA and DHA compared to that present in their diets. These data indicate that early–mid stage P. ornatus
phyllosoma have an ability to preferentially sequester, store or modify their dietary lipid composition to
support normal growth and development. These results provide important morphometric date useful in the
evaluation of larval feed and culture conditions as well as, providing baseline larval lipid nutrition data required
for the development of artificial diets for P. ornatus phyllosoma.