초록
<▼1><P>Branchial amino acid uptake is evaluated in the invasive <I>Carcinus maenas</I> and compared to native Canadian crustaceans. <SMALL>L</SMALL>-leucine transport and accumulation throughout the body of the green crab is also evaluated in various gill and organ tissues in fed and fasted states.</P></▼1><▼2><P><B>Abstract</B></P><P>Many aquatic species are well known as extremely successful invaders. The green crab (<I>Carcinus maenas)</I> is an arthropod native to European waters; however, it is now known to be a globally invasive species. Recently, it was discovered that the <I>C. maenas</I> could transport nutrients in the form of amino acids across their gill from the surrounding environment, a feat previously thought to be impossible in arthropods. We compared the ability for branchial amino acid transport of crustacean's native to Canadian Pacific waters to that of the invasive <I>C. maenas</I>, determining if this was a novel pathway in an extremely successful invasive species, or a shared trait among crustaceans. Active transport of <SMALL>L</SMALL>-leucine was exhibited in <I>C. maenas, Metacarcinus gracilis</I>, <I>Metacarcinus magister</I>, and <I>Cancer productus</I> across their gill epithelia. <I>Carcinus maenas</I> exhibited the highest maximum rate of branchial <SMALL>L</SMALL>-leucine transport at 53.7 ± 6.24 nmolg<SUP>−1</SUP> h<SUP>−1</SUP>, over twice the rate of two native Canadian crustaceans. We also examined the influence of feeding, gill specificity, and organ accumulation of <SMALL>L</SMALL>-leucine. Feeding events displayed a heavy influence on the branchial transport rate of amino acids, increasing <SMALL>L</SMALL>-leucine transport rates by up to 10-fold in <I>C. maenas</I>. <SMALL>L</SMALL>-leucine displayed a significantly higher accumulation rate in the gills of <I>C. maenas</I> compared to the rest of the body at 4.15 ± 0.78 nmolg<SUP>−1</SUP> h<SUP>−1</SUP>, with the stomach, hepatopancreas, eyestalks, muscle tissue, carapace and heart muscle exhibiting accumulation under 0.15 nmolg<SUP>−1</SUP> h<SUP>−1</SUP>. For the first time, the novel transport of amino acids in Canadian native arthropods is described, suggesting that branchial amino acid transport is a shared trait among arthropods, contrary to existing literature. Further investigation is required to determine the influence of environmental temperature and salinity on transport in each species to outline any competitive advantages of the invasive <I>C. maenas</I> in a fluctuating estuarine environment.</P></▼2>