Sciaena umbra (Linnaeus, 1758)
The upper part of an otolithus of S. umbra. I wonder if this individual was five years old, when I look at this upper part of its otolithus, which carries the obvious five clear lines.
Photos of both sides of the otolithus of a relatively large drum specimen. Photos by MCH/Andreas I. Iliopoulos
This secretive nocturnal meagre is appreciated very much as a food fish, but the recent years their numbers are decreased in the area. Usually found schooling in rocky environments reef associated at depths between 5 m and 100 m, but animals are also found even at 200 m.
Their small groups are found in caves and holes, hangs, drop offs and vegetated areas preying upon fishes, shrimps and several crustaceans.
They are long living animals showing longevity of over twenty years in the wild and they may reach commonly up to about 30 cm of length, while there are animals measuring up to 70 cm of (TL) length. Individuals larger than 25 cm are sexually matured fishes. They spawn from March to August and their larvae develop planktonic.
A very good choice to Mediterranean tanks if kept in a small school in an aquascape with lot of hiding spots and relatively massive tanks.
Otolithus is the organ that fishes have for an auditive tool as we have the eardrums. Phillipos Skarpetis, the guy who gave me this – and whom I thank a lot in public – told me that the fishes of the species maybe use it to produce sounds, as he has heard clicking sounds from these animals after he had killed one by his spear gun (you see he is an accurate underwater free diving hunter). It is known already the behaviour of the sexually matured ♂♂, which they actually produce croaking noises during the breeding period, by their swim bladders. The special structure of their bladder also gives the ability to these animals for excellent buoyancy without the use of their fins or with a minimum of their use.
Phillipos is also a craftsman and he runs a jewellery atelier and shop in the old town of Rhodos and as a clever guy he thought of using the otolithus taken from his kills as jewellery items. The fact is that he hasn’t harvest lot of drums (a common name that indicates that the animals are able to produce sounds) due to the fact that the animals are becoming rare and rarer by time in our waters and the ones that are found occur in far deeper waters than 25 m, where he usually dives, but he had used the otolithus from his catches in his craftsmanship with a great success up to now.
In Turkey they use the powdered otolithus as a treatment for diseases related to urinogenital system.
The texture of the otolithus is hard but a bit like waxy and that make them a remarkable item for crafts and very difficult for someone unaware to understand what material is this.
Otolithus, by the way, is one of the two parts of a fish, which reveal us the age of an individual. The second is the scale and both parts are used the same way we use the lines found in a cut stub to find the age of the tree.