The Creek Whaler (Carcharhinus fitzroyensis) is a common species of requiem shark, and part of the family Carcharhinidae, endemic to northern Australia. It can be found in shallow waters close to shore, including estuaries. It is a brownish plain colored shark. It is not a threat to humans.
Family: Carcharhinidae – Requiem sharks
Genus: Carcharhinus
Species: fitzroyensis
Phylum– Chordata
Class– Chondrichthyles
Subclass– Elasmobranchii
Common Name– Ground Sharks
Family– Carcharhinidae
Common Name– Requiem Sharks
Genus– Carcharhinus
Species– fitzroyensis
Status: IUCN Red List LEAST CONCERN
Average Size and Length: The Creek Whaler usually grows to about 3.3 to 4.3 feet long. The maximum recorded length is 4.9 feet long.
Teeth and Jaw: The Creek whaler has long snout with short furrows at the corners. There are 30 upper and 28–30 lower tooth rows. The upper teeth are long and triangular with strongly serrated edges and become increasing angled towards the sides of the jaw. The lower teeth are slender and upright with finely serrated edges.
Head: It is long and shaped like a parabola with large nostrils covered by skin flaps. The eyes are circular and medium sized and have nictitating membranes.
Denticles: The skin of the Creek Whaler is covered by dense, overlapping dermal denticles, each having three to five horizontal ridges leading to marginal teeth.
Tail: The Creek Whaler has a crescent-shaped notch on the caudal peduncle just before the origin of the upper caudal fin lobe. It has an asymmetrical caudal fin has a well-developed lower lobe and a longer upper lobe with a ventral notch near the tip.
Demographic, Distribution, Habitat, Environment and Range: The Creek Whaler can be found in northern Australia, between Gladstone in central Queensland and Cape Cuvier in Western Australia. It is a common species that inhabits estuaries and inshore waters from the intertidal zone to a depth of at least 130 feet.
Diet: The Creek Whaler feeds mostly on small teleost fishes like threadfin breams and lizardfishes. It also feeds on crustaceans like penaeid prawns and mantis shrimps. On occasion, cephalopods are also consumed.,
Aesthetic Identification: The Creek Whaler is stalky, and spindle shaped with 5 pairs of short gill slits. It is bronze to brownish gray above and counter-shaded pale below. It does not have an obvious lighter band on the flanks. On occasion, some sharks may be light bluish gray above.
The pectoral fins are large and triangular, with rounded to pointed tips. The large first dorsal fin originates over the rear of the pectoral fin bases. The second dorsal fin is tall and long and originates over or slightly behind the anal fin origin. There is no ridge between the dorsal fins. The anal fin is larger than the second dorsal fin.
Biology and Reproduction: Known parasites of the Creek Whaler include the tapeworm Callitetrarhynchus gracilis, and a nematode in the genus Pulchrascaris.
The Creek Whaler is viviparous. Females produce litters anywhere from 1 to 7 pups every year. Mating occurs between May and July, with the females storing the sperm until ovulation takes place between July and September. The gestation period ranges from 7 to 9 months, birthing occurs between February and May of the following year. The newborns measure 14–20 inches long and spend their first few months of life in shallow, inshore nursery areas such as Cleveland Bay in north Queensland. Males and females reach sexual maturity at lengths of around 33–35 inches and 35–39 inches.
Behavioral Traits, Sensing and Intelligence: Behavioral traits, intelligence and sensing of Creek Whalers are poorly recorded.
Creek Whaler Shark Future and Conservation: The Creek Whaler is a minor bycatch of inshore gillnet fisheries operating in northern Australia; the meat is sold for human consumption.
Creek Whaler Recorded Attacks on Humans: No threats to humans.