TY - JOUR
T1 - Adaptations to in situ feeding
T2 - Novel nutrient acquisition pathways in an ancient vertebrate
AU - Glover, Chris N.
AU - Bucking, Carol
AU - Wood, Chris M.
PY - 2011/10/22
Y1 - 2011/10/22
N2 - During feeding, hagfish may immerse themselves in the body cavities of decaying carcasses, encountering high levels of dissolved organic nutrients. We hypothesized that this feeding environment might promote nutrient acquisition by the branchial and epidermal epithelia. The potential for Pacific hagfish, Eptatretus stoutii, to absorb amino acids from the environment across the skin and gill was thus investigated. L-alanine and glycine were absorbed via specific transport pathways across both gill and skin surfaces, the first such documentation of direct organic nutrient acquisition in a vertebrate animal. Uptake occurred via distinct mechanisms with respect to concentration dependence, sodium dependence and effects of putative transport inhibitors across each epithelium. Significant differences in the absorbed amino acid distribution between the skin of juveniles and adults were noted. The ability to absorb dissolved organic matter across the skin and gill may be an adaptation to a scavenging lifestyle, allowing hagfish to maximize sporadic opportunities for organic nutrient acquisition. From an evolutionary perspective, hagfish represent a transitory state between the generalized nutrient absorption pathways of aquatic invertebrates and the more specialized digestive systems of aquatic vertebrates.
AB - During feeding, hagfish may immerse themselves in the body cavities of decaying carcasses, encountering high levels of dissolved organic nutrients. We hypothesized that this feeding environment might promote nutrient acquisition by the branchial and epidermal epithelia. The potential for Pacific hagfish, Eptatretus stoutii, to absorb amino acids from the environment across the skin and gill was thus investigated. L-alanine and glycine were absorbed via specific transport pathways across both gill and skin surfaces, the first such documentation of direct organic nutrient acquisition in a vertebrate animal. Uptake occurred via distinct mechanisms with respect to concentration dependence, sodium dependence and effects of putative transport inhibitors across each epithelium. Significant differences in the absorbed amino acid distribution between the skin of juveniles and adults were noted. The ability to absorb dissolved organic matter across the skin and gill may be an adaptation to a scavenging lifestyle, allowing hagfish to maximize sporadic opportunities for organic nutrient acquisition. From an evolutionary perspective, hagfish represent a transitory state between the generalized nutrient absorption pathways of aquatic invertebrates and the more specialized digestive systems of aquatic vertebrates.
KW - Absorption
KW - Amino acid
KW - Dissolved organic matter
KW - Feeding physiology
KW - Gill
KW - Integument
UR - http://www.scopus.com/inward/record.url?scp=80052692718&partnerID=8YFLogxK
U2 - 10.1098/rspb.2010.2784
DO - 10.1098/rspb.2010.2784
M3 - Journal Article
AN - SCOPUS:80052692718
SN - 0962-8452
VL - 278
SP - 3096
EP - 3101
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
IS - 1721
ER -