Madeira Canary Islands Azores – Fishes Dr. Peter Wirtz

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Jacks (Carangidae)
Guelly jack (Pseudocaranx dentex)
Up to 80 cm long. Madeira, Canary Islands, Azores. 2 – 200 m depth.
Despite their German name “Stachelmakrelen” (i.e. spiny mackerels), jacks are not related to mackerels (just
as the guinea pig is not a pig). Guelly jacks move in small groups or in large schools of several thousand
animals, close to the bottom and through the open water. Young animals have conspicuously yellow fins and
like to sieve through the sand for edible stuff. Searching for small crustaceans and molluscs, they can even
turn over stones! The yellow colour of the fins is much less conspicuous in adult animals (see insert). A small
black spot at the rear of the gill cover. Photos Peter Wirtz.
Blue runner (Caranx crysos)
Up to 55 cm long. Madeira, Canary Islands, Azores. 10 – ? m depth.
Blue runners move in schools through the open water, occasionally near the shore. They can be recognized by
their dark tail fins and a silvery double-line behind the gill covers, which, however, can be seen only when the
light is right. The Black jack Caranx lugubris (insert) can easily be recognized by its steep head profile. It
can be seen in the open water and in caves. It is a tropical species, that may occasionally be encountered at the
Canary Islands and (only very rarely) at Madeira. It grows to 90 cm length. Photos Peter Wirtz.
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