It is one of the smallest specimens of hammerhead shark. It is known by several names: smalleye hammerhead for its tiny eyes, curry shark or golden hammerhead for its bright metallic golden coloring and Sphyrna studies its scientific name.
1) Family tree
The Golden Hammerhead (Sphyrna tudes) is a small subtropical hammerhead shark of the Sphyrnidae family, like most hammerhead sharks like the great hammerhead, Scalloped hammerhead, Carolina hammerhead and Bonnethead.
2) A gold color
They remain one of the easiest to identify thanks to their colouring. This is one of its most distinctive characteristics. The coloration of this shark can range from bright gold in sharks from 55 to 70 cm long to orange yellow. Its skin may have a metallic or iridescent hue. As the shark ages and matures sexually, the golden colours begin to fade. Nevertheless, a yellowish grey colour will always be visible on the underside.
Its distinctive golden colouring was unknown to science. The first detailed study of the golden hammerhead shark was carried out in 1985-1986. José Castro, from Clemson University of the Food and Agriculture Organization of the United Nations (FAO), was in charge of carrying it out. 🔬
Origin of its colour
The origin of its colour is related to its diet. Juvenile smalleye hammerhead collect pigment from shrimp, while older specimens catch it from ariid catfish and their eggs, both covered with bright yellow mucus. There is no direct link that would confirm that the carotenoid pigment in catfish also comes from shrimp. 🦐
In order to provide a basis for comparison Another species of shark has been observed in the region, the yellow sighthound (Mustelus higmani), which also feeds on shrimp and also has a yellowish colour.
It is often taken as a by-catch in shrimp farms, but is not considered a commercially important species.
3) A small size for a hammerhead
It is one of the smallest hammerhead sharks in the Sphyrnidae family
Its maximum size is about 1.34 metres long for a male and 1.48 metres for a female. They can reach a maximum weight of 9 kg. This is small compared to the largest hammerhead shark (Sphyrma mokaran), which can reach 6 meters long.
Its head reaches an average length of about 130 cm (51 inches). At most it can measure 148 cm (58 inches).
4) A distinctive morphology
The golden hammerhead has a distinctly flat cephalophyll (hammer head) in the shape of an arch. Compared to his parents his eyes are extremely small because of his habitat in muddy coastal waters hence his name smalleye hammerhead. The teeth are long and thin with serrated cupsides.
It also has a mark in the center of its snout which can be a plus to differentiate it from other species. In addition, a second dorsal fin and a prolonged anal fin can be observed. And the best for the end, its exceptional golden colouring.🌟
- Golden colouring
- Flat hammer head in the shape of an arch
- deep notch in the center of his snout
- 2nd dorsal fin and extended anal fin
5) Habitat of Golden hammerhead
This little hammerhead lives in the tropical and subtropical waters of the western Atlantic Ocean. It is found mainly along the east coast of South America from Venezuela, Trinidad, Brazil and Uruguay 🏠. Mainly in turbid waters between 5 to 40 m (16 to 131 feet) deep, on muddy bottoms.
- Newborns and very young sharks, about 40cm long, reside in very shallow waters, then move to deeper waters.
- Young males and adults move with other individuals of the same size and are abundant at a depth of 27 to 36 m (89 to 118 feet).
- Adult females, on the other hand, move in shallow water between 9 to 18 m (30 to 59 feet).
Finally, it occurs in salinity ranges between 20 and 34 ppm (ppm is the indicator of water hardness).
This hammerhead shark species can swim in brackish waters (this term means that the total concentration of dissolved salt is between 1 and 10 g/l while on average it is 35 g/l for seawater.
6) Diet and prey
It feeds on small fish. But it also seems to eat, scalloped hammerhead sharks (Sphyrna lewini) newborns in addition to soft-shell animals.
Adult golden hammerhead sharks generally feed on bony fish 🐠. The catfish of the Ariidae family as well as their eggs and one of their favourite dishes. Young golden hammerhead sharks less than 67 cm long feed on penaeid shrimp.
Other food products include grunts, squid, crabs and scalloped hammerhead sharks.
Due to its size, it remains prey to more massive sharks, such as bull sharks, and larger species of hammerhead sharks.
An electro asset for hunting
The lobes of the hammer head are located where its electro-receptors are located, which allow it to help it detect prey by detecting the small electrical impulses released by it when it contracts its muscles.
The breeding method of this hammerhead shark is viviparous 💛 (i. e. it reproduces in a sedentary manner).
They reach sexual maturity after reaching a certain length:
- For females about 120 cm (47 inches),
- For males about 110 cm (43 inches).
After 10 months of gestation, the female gives birth to 5 to 19 young, the smallest curry shark measuring almost 30 cm in length.
The preferred growing area for this species in the southeast Caribbean, near Venezuela in Trinidad.
8) Preservation of golden hammerhead
Even if its fins and meat are sold, it is not considered to be of great financial importance.
However, the number of smalleye hammerhead sharks is decreasing in Venezuela and northern Brazil. Indeed, its reproductive cycle is slow. And as this is one of the most abundant species on the east coast of South America.
it is regularly caught, even accidentally, in the nets of shrimp trawlers in Tabago and Trinidad. This results in a decrease in its species. Moreover, the number of golden hammerheads during commercial capture has been reported.
It has been assessed as "vulnerable" 🆘and is on the IUCN (World Conservation Union) Red List, which is a global union of several States: government agencies and non-governmental organizations that are partners in assessing the conservation status of species.
9) Golden hammerhead shark and the man
Totally harmless. Due to their small size the curry shark does not represent any threat to man.