Trachinus radiatus, the Starry Weever (a.k.a. Streaked Weever) is a subtropical marine fish belonging to the genus of weevers, which consists of seven extant species. Six of the genus representatives inhabit the waters of the Eastern Atlantic Ocean, three of which also occurring in the Mediterranean Sea and the thus the Maltese Islands.
Weevers are sometimes erroneously called ‘weaver fish’, although the word is unrelated. In fact, the word ‘weever‘ is believed to derive from the Old French word wivre, meaning serpent or dragon, from the Latin vipera. It is sometimes also known as the viperfish, although it is not related to the viperfish proper (i.e., the stomiids of the genus Chauliodus).
The genus name, given by Linnaeus, is from trachina, the Medieval Latin name for the fish, which in turn is from the Ancient Greek τρᾱχύς trachýs ‘rough’.
The genus Trachinus belongs to the family Trachinidae, order Trachiniformes, class Actinopterygii, phylum Chordata and kingdom Animalia.
The Starry Weever grows up to 37 centimetres in length. Its body is elongated and laterally compressed. The head is large, with a wide mouth diagonally facing upwards, and its eyes positioned at the top. The branchial operculum (dorsal fins and gills) has a long spine pointing backwards.
Trachinus radiatus has two dorsal fins. The first is short with 6 venomous spiny rays. The second dorsal fin is very long with quite soft rays. Its colour varies mainly from yellowish-brown to light greyish-brown, with numerous dark spots.
The Starry Weever, like all weevers, are unusual in not having swim bladders, as do most bony fish. As a result, they sink as soon as they stop actively swimming. During the day, the Starry Weever buries itself in the sand, just showing its eyes, and snatches prey as it comes past, which consists of shrimp and small fish.
Although extremely unpleasant, stings from Trachinus radiatus are not generally dangerous and the pain will ease considerably within a few hours, even if untreated. Complete recovery may take a week or more. Quite rarely, swelling and/or stiffness may persist for months after envenomation.
First aid treatment consists of immersing the affected area in hot water, as hot as the victim can tolerate without being scalded. This will accelerate denaturation of the protein-based venom. The use of hot water will reduce the pain felt by the victim after a few minutes. Usual experience is that the pain then fades within 10 to 20 minutes, as the water cools.
Heat should be applied for at least 15 minutes, but the longer the delay (before heat is applied), the longer the treatment should be continued. Once the pain has eased, the injury should be checked for the remains of broken spines, and if any are found, these need to be removed. Over-the-counter analgesics, such as aspirin or ibuprofen, may be of assistance in the management of pain and can also reduce edema.
If swelling spreads beyond the immediate area of injury (e.g. from hand to arm), if symptoms persist, or if any other factor causes concern, medical advice should be sought.
The photo of this Starry Weever was taken at a depth of 10m at Mġarr Ix-Xini on Gozo’s south coast.
Photo taken by Brian Azzopardi