Transcript kate&^chris
The Gasterosteiformes: A renaissance for bony armor By Christopher Bertram and, also, Kate Laskowski Superorder Acanthopterygii Acanthopterygii Traits • Ascending process – Jaw mobility and protrusibility • Pharyngeal dentition – Most developed • New muscle and bone attachment • Other – Ctenoid scales – Physoclistous gas bladder Series Percomorpha • Rumored to be most diverse group of fishes – 12,000 spp. • Defined by anteriorly placed pelvic girdle – Connected to pectoral girdle via a ligament • Pelvic fin – Anterior spine – 5 soft rays Order Gasterosteiformes • Diversity – 257 spp. • Habitat – Fresh and saltwater • Anatomy – Small mouths – Dermal armor • Almost as good as placoderms • Highly studied – – – – Behavior Physiology Ecology Evolution Family Hypoptychidae • Sand eels • Not true eels • Marine near Japan and Korea • Important food source for diving birds • Burrow into the sand to avoid predation • Understudied Family Aulorhynchidae • Tube snouts • Rigid body with small dorsal fin • Uneven jerky movement • Marine species – West coast of NA – East coast of Asia • Love kelp Family Gasterosteidae • The sticklebacks, AKA the most amazing fish ever! – Threespine – Black-spotted – Nine-spine – Brook – Four-spine – Fifteen-spine Gasterosteaus aculeatus • Found all over Northern Hemisphere • Independently derived freshwater populations = amazing study organism – Especially for behavior! • Lots of variation in spines and plating – Low plating and smaller spines selected in freshwater environments Single dad with 45 kids seeks noncannibalistic mother • Males build nests and attract females • Elaborate courtship dance • If he’s a hottie, female will dump and run • Male then: – Fans eggs – Cleans off fungus – Defends against hungry fish – Fry retrievals Family Pegasidae • Seamoths or Pegasus fish • Quite rare, only 5 spp. • Shed their scales to prevent parasite build-up • Can’t really swim so he “walks” using his ultra cool pelvic fins • • http://www.youtube.com/watch?v=6l2d6 7pgsS4 http://www.youtube.com/watch?v=FIgBj L94tDM Family Solenostomidae • Ghost pipefishes • Marine – Coastal – Tropical – Reedy area • Reproduction – Females carry eggs in brood pouch • Modified pelvic fins Family Syngnathidae • Seahorses • Unusual shape • Male parental care – Only natural male pregnancy in verts – Evolved multiple times – Breeding • Female inserts ovipositor • Egg shells dissolve • Male placenta Family Syngnathidae • Seahorses • Evolutionary consequences – Females compete for males – Sexually dimorphic • In polyandry www.youtube.com/watch?v=Vzwr RKrw7Sk&feature=related Family Syngnathidae • Pipefishes • Polyandrous mating system – One female, several males • External attachment of eggs to the male • Offspring are born freeswimming • http://www.youtube.com/watch?v=dT -Hrw7gaHQ&feature=related – (good stuff at 45 s) Family Indostomidae • Only 1 genus, 3 species • Lazy fish • Discovered in 20’s • Distribution – Marine – Thailand • Armored body – Covered in scutes Family Aulostomidae • Trumpet fishes • One genus, 3 species • Distribution – Marine – Tropical – Worldwide • Highly carnivorous – Ambush predator – They suck Family Fistulariidae • Cornetfishes • One genus, four species • Distribution – Marine – Tropical/sub-tropical • Predate on invertabrates • Not of fishing interest, except this guy • www.youtube.com/watch?v=DK9_yuo i44k&feature=related Family Macrorhamphosidae • Snipefishes • Distribution My spine is sooooo big… – Marine – Circum-global – Temperate waters • Feed on invertebrates – “Anteater of the sea,” © KL Laskowski • Size matters Family Centriscidae • Shrimpfishes • Marine only • Small family – Approximately 12 spp. • Indo-pacific distribution • Anatomy – – – – Unusual Covered in bony plates Dorsal fin long/sharp Fins moved ventrally Review of Gasterosteiformes • Generally scale-less – Heavy body armor – Pelvic girdle • Males finally pull their own weight – Male parental care – Male pregnancy • Mostly marine, shallow water critters • All predacious Questions • What’s so weird about seamoths? • Why are sticklebacks great study organisms? • Do male seahorses and pipefishes really become “pregnant”? • Where are all the fins on a shrimpfish located? • Did anyone take hand-written notes, or did you just assume this would be posted online?