Plasma tissue and haemolymph samples from 118 species across a range of phyla were assayed for the presence of saxiphilin [3H]STX, a soluble protein which binds the neurotoxin saxitoxin. Samples of individuals per species ranged from 1 to 18 and phyla were sourced from around the world.Effective concentrations of [3H]STX binding sites (pmol ml-¹) in plasma and tissue samples and (pmol mg-¹) are given for the species which exhibited activity, as well as the material tested (plasma, tissue, haemolypmph) and, in some cases, the geographical source.

To survey a range of phyla for the presence of saxiphilin-like activity.

The results suggest that the saxiphilin gene is as old as an ancestral gene encoding bilobed transferrin, identified in several arthropods and all the vertebrates in the study.Species (28) found to exhibit saxiphilin-like activity:Teleost fish: Anguilla rostrata (eel); Apogon sp. (cardinal fish); Danio rerio (zebra fish); Gambusia affinis (mosquito fish); Hypostomus plecostomus (catfish); Poecilia reticulata (guppy); Pomacentrus sp. (damsel fish)Lungfish: Protopterus aethopicusAmphibians: Ambystoma tigrinum (tiger salamander); Bufo marinus (cane toad); Notopthalamus viridescens (eastern newt); Rana sylvatica (wood frog); Rana temporaria (grass frog)Reptiles: Varanus rosenbergii (goanna monitor lizard); Sceloporus poinsetti (crevice spiny lizard); Naja naja kaouthia (Thailand cobra); Croalus viridus viridus (rattlesnake); Thamnophis ordinoides and T. sirtalis (garter snakes)Arthropods: Daphnia sp. (water flea); Oniscus sp. (sowbug); Ethmostigmus rubripes (centipede); Araneus cf cavaticus (orb web spider); Actaeodes tomentosus, Chlorodiella nigra, Liomera tristis and Lophozozymus pictor (xanthid crabs).Species (102) which did not contain a detectable amount of saxiphilin binding activity:Acanthaster planci (crown-of-thorns starfish); Acheta domestica (cricket); Acmaea cf testudinalis (limpet); Actinia australis (sea anemone); Alligator mississippiensis (alligator, North America); Anas sp. (duck); Anser anser (domestic goose); Aplysia californica (sea hare); Arothon manilensis (puffer fish); Artemia salina (brine shrimp); Asterius forbesii (starfish); Asterius vulgaris (starfish); Balaenoptera acutorostrata (minke whale); Balberus sp. (cockroach); Bos taurus (cow); Callianassa australiensis (marine yabby); Camponotus pennsylvanicus (carpenter ant); Cancer borealis (Jonah crab); Caretta caretta (loggerhead turtle); Cicada sp. (cicada); Columba lives (domestic pigeon); Crocodylus porosus (crocodile, Australia); Cucumaria frondosa (sea cucumber); Cyclopterus lumpus (lumpfish); Delphinus delphis (common dolphin); Dermestes sp. (dermestid beetle); Dermochelys coriacea (leatherback turtle); Diademnum molli (ascidian); Donax deltoides (bivalve); Drosophila melanogaster (fruit fly); Echinarachnius parma (sand dollar); Eisenia fetida (tiger worm); Elseya dentata (snapping tortoise, Australia); Equus caballus (horse); Eudrilus eugenia (nightcrawler); Gallus gallus (chicken); Gastrolepida calvigea (annelid); Ginglymostoma cirratum (nurse shark); Globicephala malaena (pilot whale); Hippodamia convergens (lady beetle); Holothuria atra (holothurian); Homarus americanus (lobster); Homo sapiens (human); Hyalophora cecropia (silkmoth); Jasps stellifera (sponge); Lagenorhynchus acutus (white-sided dolphin); Lanthella basta (sponge); Latimeria chalumnae (coelacanth); Limulus polyphemus (horseshoe crab); Linckia laevigata (starfish); Lingula sp. (brachiopod); Littorina litorea (periwinkle); Makaira indica (marlin); Manduca sexta (tobacco hornworm moth); Meleagris gallopavo (common turkey); Mordacia mordax (lamprey); Mytilus edulis (bivalve mollusc); Mytilus edulis (blue mussel); Negaprion brevirostrio (lemon shark); Notechis scutatus (Australian tiger snake); Ocypode corimana (ghost crab); Oecophylla smaragdine (green ant); Oncopeltus fasciatus (milkweed bug); Oryctolagus sp. (rabbit); Ovis aries (domestic sheep); Pagurus sp. (hermit crab); Papilio polyxenes (black swallowtail butterfly); Penaeus monodon (tiger prawn); Pericherax heteroraphis (sponge); Periplenata australiensis (cockroach); Polycarpa aurata (ascidian); Polycarpa sp. (ascidian); Pseudemys scripta (red ear turtle, North America); Pseudoceros sp. (flatworm); Pseudopleuronectes americanus (flounder); Raja erinacea (little skate); Rattus norvegicus (rat); Reteterebella queenslandia (polychaete); Reticulitermes flavipes (termite); Rhopoloides odorabile (sponge); Sarcophyton elegans; Saxidomus giganteus (butter clam); Saxidomus giganticus (bivalve mollusc); Scomber scombrus (Atlantic mackerel); Scylla serrata (mud crab); Sepia plangon (squid); Sinularia dura (soft corals); Solaster endeca (starfish); Somniosus microcephalus (Greenland shark); Sphenodon punctata (tuatara); Spirobranchus giganteus (polychaete); Spisula solidissma (clam); Squalus acanthius (dogfish shark); Stichopus chloronatus (holothurian); Strongylocentrotus droebachiensis (sea urchin); Sus scrofa (pig); Tenebrio molitor (mealworm larvae); Tunica mogula (tunicate); Uca vomeris (fiddler crab); Vepricardium multispinosum (bivalve); Xenopus laevis (African clawed frog); Xestospongia exigua (sponge).