Presentation on theme: "(Blacktip Shark and Smalltooth Sawfish) James Gill"— Presentation transcript:
1 (Blacktip Shark and Smalltooth Sawfish) James Gill Phylum: Chordata Subphylum: Vertebrata Superclass: Gnathostomata Class: Chondrichthyes Subclass: Elasmobranchii Order : Carcharhiniformes & Pristiformes(Blacktip Shark and Smalltooth Sawfish)James Gill
2 Order Carcharhiniformes: Largest Order of sharks containing 270 different species including catsharks, swellsharks, and the sandbar sharkKnown as ground sharksNictitating membrane over each eyeTwo dorsal finsAn anal finFive gill slitsFamilyFamily Carcharhinidae:Known as Requiem SharksMigratoryLive-bearing sharks (viviparous)Responsible for most attacks on humasLive in warm seas
3 Blacktip Shark (Carcharhinus limbatus) Biological Facts:Females are viviparous, usually bearing 4-7 pupsUsually grow to be about 4.9ft long90% of their diet is fish, the other 10% being crustaceans and cephalopodsFavored habitats are island lagoons, muddy bays coral reef drop-offs and mangrove swamps.Most active at dawn and duskUsually live in sexually segregated schools until mating seasonMost bites can be pinned on blacktip sharks but there has never been a recorded fatal incident.Seasonal migration from North Carolina in the summer to Florida in the winter off the east coast of the USNearly threatened but not endangeredFun Facts:Known to jump out of the water and spin in order to disorient schools of fish for feedingKnown to utilize asexual reproduction when no males are present (automictic parthenogenesis)Most timid of the large Requiem Sharks and will observe humans from a safe distance.
4 Blacktip VS Blacktip REEF sharks Carcharhinus limbatusTimid but curious, will watch humansCloser to reef drop-offs, sometimes mangrove swampsUsually 4.9 feetBlacktip Reef:Carcharhinus melanopterusTimid and skittish, very difficult to approachShallow inshore waters and sandy flatsUsually 5.3 feet
5 Order Pristiformes: Biological Facts: Known as carpenter sharks Only 1 living family(Pristidae) and 7 specieslong, narrow, flattened rostrumBiological Facts:Females are ovoviviparousLittle is known about the reproduction habits of the sawfish. They are estimated to mate once every two years, with an average litter of around eight. They mature very slowly (12 years) with low reproduction ratesUsually 7.6 meters in lengthSmall fish, crustaceans and mollusksshallow tropical and subtropical waters in coastal parts of the AtlanticAll species are nocturnalRostrum is used for a multitude of purposesAll species are critically endangered
6 Differences between sawFISH and sawSHARKS Gill openings on undersideNo barbelsAll teeth are the same sizeShallow, costal watersRelatively large (up to 23feet)Sawsharks:Gill openings on sidesBarbelsAlternating large and small saw teethDeep offshore watersRelatively small (about 5feet)
7 Fun with Rostrums- a Multi Purpose tool A sawfish’s saw is made up of thousands of sensory organs that allow them to monitor the movements of other organisms by measuring the electrical fields they emit. Because the sensory organs are more densely packed on the dorsal side of its saw, the fish can create an image of the three-dimensional area above it, even in waters of low-visibility, which helps explain its bottom-dwelling nature. Utilizing their saw as an extended sensing device, sawfish are able to “view” their entire surroundings by maintaining a position low to the sea floor.Smalltooth sawfish have been observed to approach large shoals of fish while striking their saw rapidly from side to side. The sawfish has also been observed to attack larger prey by using their weapon to dislodge large pieces of meat from victims. They then use their serrated saw teeth to tear through flesh.The rostrum’s “teeth” are called deticles. Because the fish can swing its body so quickly, it also acts as a defense mechanism to scare predators away.The pups’ rostral blades are enclosed by a sheath – so as to protect the mother during the birthing process – which eventually disintegrates and falls off.