Transcript Myliobatidae

Family Myliobatidae
Eagle Rays
Taxonomy
Aetomylaeus
Rhinoptera
Manta
Mobula
Aetobatus
Pteromylaeus
Myliobatis
Taxonomy
Manta
Mobulidae
Mobula
Superfamily
Myliobatoidea Rhinopteridae
Rhinoptera
Aetomylaeus
Myliobatidae
Myliobatis
17 species
M. californica
M. australie
Aetobatus
A. narinari
Pteromylaeus
Morphology
medium size: 1m-3m disc width
fins: wing-like pectoral
dorsal insertion behind pelvic
caudal lacking
long, whip-like tail
1-6 short stinging spines
Morphology
pavement-like teeth
1-7 rows
papillae on roof of mouth
countershaded
may have spots/bars
Morphology
rounded subrostral lobe
different from:
Rhinoptera
Manta, Mobula
Habitat and Distribution
semi-pelagic
inshore waters, up to 300m deep
associated with reefs, sandy flats, seagrass beds, lagoons,
shallow bays, estuaries
Habitat and Distribution
warm temperate-tropical
nearly worldwide- Atlantic, Pacific, Indian Oceans
some genera- limited distribution, while others
widespread
A. narinari
Reproduction
limited information
mature ~half adult size
aplacental viviparous, histotroph nutrition
M. aquila- gestation 6-8 months
2-15 pups/litter, average=4-8
synchronized repro. cycles, but in different seasons
may breed every 1-3 years, little information available
Reproduction
Behavior: Tricas 1980
close-following= olfaction-mediated reproduction?
Prey/Feeding Habits
use subrostral lobe to dig up invertebrates, esp. bivalves
Behavior
fly/glide through water column- active
may leap out of water
social- schooling
migration
Predators
sharks (hammerhead)
marine mammals
people
Human Importance
low commercial value, but increasing in seafood markets
bycatch in other fisheries
fishmeal, oil
nuiscance to bivalve fisheries
may sting fisherman, divers- Steve Irwin
Human Importance
popular in public aquariums/touch pools
Conservation Status
IUCN: data deficient, least concern
M. australie- decreasing CPUE= declining?
habitat destruction may be an issue
Literature Cited
Bester, C. 2006. Australian Bull Ray. Florida Museum Natural History, Ichthyology
Department. University of Florida. < http://www.flmnh.ufl.edu/fish/>. Downloaded on 1
December 2007.
Bester, C. 2006. Bat Ray. Florida Museum Natural History, Ichthyology
Department. University of Florida. < http://www.flmnh.ufl.edu/fish/>. Downloaded on 1
December 2007.
Bester, C. 2006. Spotted Eagle Ray. Florida Museum Natural History, Ichthyology
Department. University of Florida. < http://www.flmnh.ufl.edu/fish/>. Downloaded on 1
December 2007.
Chapman, D.D. and S.H. Gruber. 2002. A further observation of the prey-handling behavior of the great
hammerhead shark, Sphyrna mokarran: predation upon the spotted eagle ray, Aetobatus
narinari. Bulletin of Marine Science 70(3): 947-952
Gonzalez-Isais, M. and H.M.M. Dominguez. 2004. Comparative anatomy of the superfamily
Myliobatoidea (Chondrichthyes) with some comments on phylogeny. Journal of
Morphology 262: 517-535
IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 1
December 2007.