The spotted dragonet (''Callionymus maculatus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of dragonet native to the eastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

and the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

where it occurs at depths of from . This species is important to local peoples engaged in subsistence fishing.

Description

The spotted dragonet is similar in shape to the

common dragonet The common dragonet (''Callionymus lyra'') is a species of dragonet which is widely distributed in the eastern North Atlantic where it is common near Europe from Norway and Iceland southwards. It is a demersal species that occurs over sand bottom ...

(''Callionymus lyra'') but it is smaller, growing to a

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of in males and in females. It has a broad, flattened head and body which is flat ventrally and convex dorsally and has a round cross-section posteriorly. The large eyes are situated quite close to each other on the top of the head which has a quite large, protractile mouth. The snout is a little shorter than the diamerter of the eye, being markedly shorter than that of the common dragonet. The

preoperculum This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes. A B C ...

is hooked and has four spines, on pointing forwards and the remaining three point backwards. There are two high

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

s, taller in males than in females, and the first dorsal fin in males is a little higher than the second dorsal fin. The first dorsal fin has four rays and the second has 9-10 rays. The

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is similar in size to the second dorsal fin and it has a long tail. The

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

are laterally situated and the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s are fan-shaped with a broad base. Females and immature males are yellowish-brown in colour with a double row of obvious brown spots on the flanks interspersed with smaller blue spots. Along the back there are four brown saddle shaped blotches. The mature males are similar but differ in having dorsal fin with four horizontal rows of conspicuous dark spots and smaller blue spots, females having two.

Distribution

The spotted dragonet is found in the eastern North Atlantic from southern and western Iceland and Norway south to Senegal and it also occurs in the

, including the

Adriatic The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) ...

and Aegean but it is absent from the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

. In the Atlantic its range includes the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

Habitat and biology

The spotted dragonet is a

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

fish which lives on sand substrates. Like other species of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Callionymidae, this species spawns in pairs and has eggs,

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

, and

postlarvae Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The ...

which are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

. In a study conducted off the coast of

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

, the spawning season of the spotted dragonet was ascertained to extend from April to September, the females reached maturity faster than males and are serial spawners, and males may reach first maturity at different ages. The rays of the dorsal, anal and caudal fins grow at equal rates in females but grow at different rates in males after maturity has been reached. This species feeds mainly on polychaetes and amphipods, but

bivalves Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

s and

brittle stars Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomot ...

are also frequent components of its diet. Smaller specimens take more amphipods and fewer polychaetes than the larger individuals. Abstract

Human usage

The spotted dragonet is taken as bycatch but is normally discarded in the beach seine fishery on the central coast of Portugal. Dragonets are sometimes taken as bycatch in bottom trawls and marketed locally and some species are commercially used in the

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

trade.

References

{{Taxonbar, from=Q772858 M Fish described in 1810 Taxa named by Constantine Samuel Rafinesque