Oral and integumental uptake of free exogenous glycine by the Japanese spiny lobsterPanulirus japonicusphyllosoma larvae

Abstract

-1). Thus, the results of this study provide clear confirmation that, in addition to the known mode of oral feeding on macroscopic food masses, P. japonicus phyllosoma larvae are also able to absorb nutrients directly from the surrounding medium.

Shape shifting predicts ontogenetic changes in metabolic scaling in diverse aquatic invertebrates

“…they can absorb oxygen and expel dissolved waste products such as CO 2 through their thin, permeable integuments) [40,41]. Some can even absorb nutrients through their body surfaces and metabolize them in their tissues [40,42]. Remarkably, the body-mass scaling slope for metabolism in larvae of the Pacific oyster Crassostrea gigas is not significantly different from that for uptake of the amino acid alanine [40].…”

Uptake of dissolved free amino acids by spiny lobster Panulirus japonicus phyllosoma larvae

“…In the past, it was believed that the exoskeleton represented an insurmountable barrier to the uptake of dissolved nutrients in arthropod larvae [23,24], and Tonheim et al [22] suggested that methionine was absorbed by Artemia through the gut, with drinking water. However, in a study using isotope-labeled glycine, we have established that the uptake of this AA in Japanese spiny lobster phyllosoma larvae occurs not only via orally ingested water but also, and perhaps primarily, through the integument [21]. This was the first demonstration of integumental absorption of dissolved nutrients in this phylum.…”

“…Triplicate water samples were taken from each bowl at 0, 0.5, 1, 2, and 5 h after introduction of the larvae to the bowls. This sampling schedule was based on results from preliminary experiments that showed large individual variability of uptake rates by the larvae in the first hours of incubation and relative stability after 5 h ( [21]; S.C. Söylemez, unpublished results). Samples were taken using 1 ml syringes, passed through a Whatman 0.2 lm PVDF filter, and stored in Eppendorf tubes at -80°C until [27,28] analysis.…”

“…Previous studies have shown that phyllosoma larvae of the Japanese spiny lobster Panulirus japonicus have the capacity to ingest the amino acid glycine and other nutrients from the major classes (proteins, lipids, and carbohydrates) that were dissolved or dispersed in seawater [20,21]. More recently, it was shown also that the nauplii of another member of phylum Arthropoda, Artemia, incorporated free methionine during incubation in medium containing this amino acid (AA) [22].…”

“…Thus, in addition to glycine, which was tested in a previous experiment [21], we tested six other L-type AAs including aspartic acid, threonine, glutamic acid, alanine, valine, and methionine. We also examined the time course of uptake during 5 h of incubation and the effect of substrate concentration on the rate of AA absorption.…”