Halfbeak

The Halfbeak is the fish that makes most people stop and ask what exactly they are holding. It looks like a Garfish with half its mouth missing.

And that is precisely the difference. In the Garfish both jaws are drawn out into a long beak, like a pair of tweezers. In the Halfbeak only the lower jaw is extended, while the upper stays short and triangular, like a lid closing over it. They are two different families, the Hemiramphidae and the Belonidae.

The body is long and slightly compressed, with a dark bluish green or grey back and a silvery belly. The dorsal and anal fins sit far back, close to the tail. One detail gives the family away at once: the tip of the lower jaw is red.

Three species live in the Mediterranean, separated by two simple features: the scales on the upper jaw, and the shape of the tail.

Hemiramphus far. The upper jaw is naked, without scales. The tail is deeply forked with the lower lobe noticeably larger, and the upper lobe yellowish. The anal fin begins below the middle of the dorsal fin base. It normally carries 4 to 6 black spots along the flanks, but be careful: in the Mediterranean population those spots are often faded or entirely absent, so their absence does not rule the species out. It is by far the most common and reaches 45 centimetres.

Hyporhamphus affinis. The upper jaw carries small scales. The tail is forked as well, but the anal fin starts further forward, below the first third of the dorsal fin base. The back is dark bluish green and there are no spots. It is very rare in the Mediterranean.

Hyporhamphus picarti. The upper jaw has scales, but the tail is what sets it apart: it is only slightly forked, with the inner rays more than half the length of the outer ones. It is the smallest of the three and the only native one.

This is a surface fish. It lives in the top few metres of the water column and close to shore, in bays, harbours and shallow sandy places.

It always moves in schools, often large ones. Its most distinctive behaviour comes when it is disturbed: it leaps and skitters across the surface with half its body out of the water, cutting the sea like a skimmed stone.

Hyporhamphus picarti prefers even shallower water and often enters estuaries and brackish areas.

The two species feed differently, which is why they coexist without competing.

Hemiramphus far feeds on zooplankton and on whatever floats at the surface, gathering food as it moves through the top few centimetres of water.

Hyporhamphus picarti does the opposite. It drops down near the bottom and grazes algae and organic debris from the surface of the sediment.

Its eggs are unusual for a surface fish. They are large and carry sticky filaments with which they attach to floating objects or to things on the bottom. Hyporhamphus picarti fastens them to underwater vegetation.

So the eggs are not swept away by the currents as with most pelagic species, but stay anchored until they hatch.

Hemiramphus far matures sexually at around 23 centimetres, and the greatest recorded age is 4 years.

In the eastern Mediterranean its large schools are caught mainly with purse seine and occasionally in trammel nets, contributing to the local fisheries of the Levant.

Like many surface fish it is strongly drawn to light at night, which often brings it close to lit jetties and boats.

The flesh is edible, though the fish is slender and bony, so in Greece and Cyprus it does not carry the commercial value it has elsewhere. Tellingly, it does not appear at all in the official Greek register of commercial fishery names.

Two of the three species are Lessepsian, meaning they entered the Mediterranean from the Red Sea through the Suez Canal. Their fortunes could hardly have been more different.

Hemiramphus far succeeded. Its spread is among the best documented of any: first recorded in Palestine in 1927, then Syria in 1931, Rhodes in 1938, Egypt in 1994, Tunisia in 2004 where the population increased, Algeria in 2012 and Lampedusa, Italy, in 2014. The CIESM atlas of exotic fishes now describes it as very abundant in the Eastern Basin, up to the Sicily Strait. If it seems to you that you are seeing it more often in recent years, you are not imagining it.

Hyporhamphus affinis came through Suez as well but never established. CIESM calls it very rare, with only isolated captures: Lebanon in 1964, the Syrian coast in 2005, Iskenderun Bay in Turkey in 2007 and Tunisia in 2007. If you find a halfbeak in our waters, the odds overwhelmingly favour Hemiramphus far.

Two names you will meet that do not hold. This family has been plagued by misidentification. Many sources, encyclopedias included, list Hemiramphus marginatus for the Mediterranean: that goes back to the first Mediterranean record of 1927, published under that name in error, while the species is in fact restricted to the Red Sea and the Persian Gulf. Likewise, the first Lebanese captures of Hyporhamphus affinis were published as Hyporhamphus dussumieri.

Hyporhamphus picarti has the opposite story. It was taken for a Lessepsian migrant in 1953, until the same researcher recognised the error in 1966. It is native to the Mediterranean and also occurs in the eastern Atlantic, from Gibraltar and Morocco down to Angola. The IUCN lists it as Least Concern.