Sex-specific seasonal variation in the carotenoid content of sea urchin gonads

Abstract

This study documents the effect of sex on gonad carotenoid content during the annual reproductive cycle of Strongylocentrotus droebachiensis from northern Norway. Male and female S. droebachiensis exhibited distinctly different patterns of carotenoid variation, with seasonal carotenoid depletion and replenishment in females and carotenoid retention in males. Females lost approximately 71.1% of their echinenone during spawning, and compensated for the loss by active deposition during gonad regrowth. Female carotenoid levels (100 to 275 µg g -1 dry mass), although lower and less variable than male carotenoid levels, were consistently higher than predicted by estimates based on a constant post-spawning carotenoid content. Males did not lose carotenoids during spawning, and the concentration of carotenoids in male gonads varied from > 600 to < 200 µg g -1 dry mass, apparently as a passive result of increasing gonad size. The results suggest that carotenoid supplements in urchin diets would be largely wasted in gonad enhancement cultivation of male S. droebachiensis, and emphasize the importance of controlling future feeding trials for the confounding effect of sex on carotenoid deposition.

A Novel Fatty Acid-Binding Protein-Like Carotenoid-Binding Protein from the Gonad of the New Zealand Sea Urchin Evechinus chloroticus

“…The assimilation of carotenoids in the gonads suggests that they play an important role in sea urchin reproduction. In support of this hypothesis, it has been observed that gonad carotenoid concentrations fluctuate in accordance with the annual reproductive cycle [9], [19]. Furthermore, it has been demonstrated that carotenoids are incorporated into oocytes and may provide anti-oxidant protection to spawned eggs and juveniles during early development [20], [21], [22].…”

Carotenoid composition of a New Zealand (Evechinus chloroticus) and an Australian (Heliocidaris erythrogramma) sea urchin in relation to gonad colour

“…Protein, lipids, carotenoids and other nutrients build up in the gonads prior to spawning (Borisovets et al, 2002;Griffiths & Perrott, 1976;Hagen et al, 2008;Tsushima & Matsuno, 1990). Protein, lipids, carotenoids and other nutrients build up in the gonads prior to spawning (Borisovets et al, 2002;Griffiths & Perrott, 1976;Hagen et al, 2008;Tsushima & Matsuno, 1990).…”

Carotenoids in Aquatic Ecosystems and Aquaculture: A Colorful Business with Implications for Human Health

“…Male sea urchins may not require annual carotenoid replenishment because sperm does not contain carotenoids and overall carotenoid content in male gonads tends to be seasonally stable. When males reach a saturation threshold for echinenone either the uptake or bioconversion of β,β-carotene is curtailed (Hagen et al, 2008). High-quality sea urchin gonads have a uniform yellowish-orange color which is a reflection of its carotenoid content, and substandard color is a direct result of carotenoid levels being either too low, leading to paleness or too high, leading to dark miscoloration (i.e., dark red/brown).…”

“…The gonadas of sea urchins exhibit a pattern of seasonal carotenoid depletion and replenishment in females and carotenoid retention in males (Hagen et al, 2008). Echinenone is preferentially incorporated into the eggs and therefore female urchins need to replenish their echinenone content on an annual/seasonal basis.…”

“…When feeding on Rhodophycea algae (i.e., lacking fucoxanthin), the predominant pigments in the gut wall of sea urchins are chlorophyll-a, lutein and zeaxanthin (Haug et al, 2003). Echinenone is the primary carotenoid in the gonads of edible sea urchins (Matsuno and Tsushima, 2001) and its content is limited by the availability, uptake and bioconversion of β,β-carotene from natural dietary sources (Tsushima, 2007;Hagen et al, 2008). Symonds et al (2007) proposed two alteranative routes of conversion of all-trans β-carotene into 9 ′ -cis-echinenone noting that neither the all-trans nor 9 ′ -cis forms of echinenone occur in the natural diet of wild Paracentrotus lividus and the presence of both forms of echinenone in the gut wall demonstrates their formation in situ via the metabolism of other dietary carotenoids.…”