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Guinean amberjack (Seriola carpenteri): the amberjack that looks like the greater amberjack from the outside

From the outside, according to Italian Wikipedia, it cannot be told apart from the greater amberjack — and yet it is a species of its own. *Seriola carpenteri* was only described in 1971 and is called Guinean amberjack in English (FishBase, GBIF), sériole guinéenne in French, medregal de Guinea in Spanish, charuteiro-da-Guiné in Portuguese, viirupiikkimakrilli in Finnish (GBIF) and ricciola della Guinea in Italian (Italian Wikipedia). Its home is the eastern Atlantic off West Africa; according to the CIESM Atlas it reached the Mediterranean through the Strait of Gibraltar, not through the Suez Canal. To this day the Atlas lists three records there. Here is what the sources know about it, how it can be recognised at all — and how little of that is certain.

Named after a big-game angler

It was described by Mather in 1971 (FishBase, Dutch and Swedish Wikipedia). The species name honours William K. Carpenter: according to FishBase a big-game angler and friend of the author, according to English Wikipedia from Fort Lauderdale in Florida, for a long time president and most important patron of the International Game Fish Association, who supported marine research with money and his own participation. The genus name *Seriola* is, according to FishBase, a Latin diminutive meaning “large earthenware pot”. The fact that the species got its name so late has consequences: because it was only described in 1971 and looks so similar to the greater amberjack (*Seriola dumerili*), mapping its occurrence is extremely difficult, according to Italian Wikipedia.

How to recognise it

  • Externally like the greater amberjack. Italian Wikipedia calls its appearance identical to that of *S. dumerili* and lists only three differences: smaller size, the number of spines in the first dorsal fin and the number of gill rakers.
  • Gill rakers are the best feature. The CIESM Atlas gives 22–23 for *S. carpenteri*. In *S. dumerili* the number drops with growth from 18–24 in small fish to 11–19 in fish over 20 cm fork length (CIESM Atlas). A greater amberjack of more than 20 cm therefore has fewer rakers than *S. carpenteri* — though they can only be counted on a fish that has been caught.
  • Lobe of the second dorsal fin: in adults as long as the pectoral fin or slightly longer, usually 15–18 % of fork length. In *S. rivoliana* it is longer, usually 19–22 % (CIESM Atlas).
  • Broad end of the upper jaw. The rear end of the upper jaw is relatively broad. In *S. fasciata* it is relatively slender, and the eye is relatively large there (CIESM Atlas).
  • Adults dark pink on the back and flanks, darker on the head, pale on the belly (CIESM Atlas).
  • Juveniles with five bars. Below 20 cm fork length they are yellow with five dark, irregularly interrupted vertical bars that do not extend onto the membranes of the soft dorsal and anal fins; a sixth, small dark bar sits at the end of the caudal peduncle (CIESM Atlas).
  • No bony scutes along the lateral line, but grooves on the caudal peduncle (CIESM Atlas).
  • Fin formula: first dorsal fin with 7–8 spines, second with one spine and 28–33 soft rays, anal fin with 17–21 soft rays, pectoral fin with 20 rays (CIESM Atlas).

148 fish off Lampedusa

The Mediterranean record was published by Pizzicori, Castriota, Marino and Andaloro in 2000 in the *Journal of Fish Biology* — under the title *“Seriola carpenteri: a new immigrant in the Mediterranean from the Atlantic Ocean”*. The CIESM Atlas reproduces two records from it: 20 fish in August 1996 and 148 fish in September 1997, both off Lampedusa. After that the Atlas lists only one more: three fish in 2016 off northern Tunisia (Capapé and colleagues, 2018, *Cahiers de Biologie Marine* — judging by the title, the first confirmed record on the Tunisian coast). English Wikipedia sums it up like this: since 2000, a few times in the Strait of Sicily. The species is native to the eastern Atlantic: according to FishBase from the Bay of Biscay and from Agadir in Morocco to Angola, including Cape Verde. For the Bay of Biscay the Atlas cites a paper by Quéro from 1986 which, judging by the title, reported the species as new to the fauna of the north-east Atlantic.

Habitat, prey, spawning season

  • Adults over the shelf. They live near the seabed up to the open water above it (benthopelagic), generally confined to coastal waters over the continental shelf, from the surface to at least 200 m depth (CIESM Atlas, FishBase).
  • Juveniles in open water. They live near the surface in the open sea or in offshore shelf waters (CIESM Atlas).
  • Warm water. The species is generally confined to areas where the surface temperature is above 25 °C; its distribution is possibly influenced by the seasonal shifts of the 18–27 °C water mass along the African coast (FishBase, CIESM Atlas, English Wikipedia).
  • Prey: squid and fish (FishBase, CIESM Atlas, English Wikipedia). From this FishBase calculates a trophic level of 4.6.
  • Probably spawns in August and September (CIESM Atlas). The eggs drift in open water (FishBase). According to the Atlas, the species is smaller at sexual maturity than *S. dumerili*, which first spawns at 91 cm total length; neither the Atlas nor FishBase gives a size at maturity of its own for *S. carpenteri*.
  • Otherwise little known. Its biology is little known, writes the CIESM Atlas. Italian Wikipedia suspects that its way of life does not differ substantially from that of the greater amberjack.
  • Conservation status: Least Concern on the IUCN Red List (assessed on 14 April 2014). FishBase rates the resilience of the stock as medium (doubling time 1.4–4.4 years) and its vulnerability to fishing as moderate (42 out of 100).

Probably in the catch under the wrong name

In the Atlantic, according to the CIESM Atlas, it is mostly caught with pelagic trawls, bottom trawls, purse seines and gill nets. FishBase lists it as commercially used and as a game fish and assigns it to the price category “very high”. In the Mediterranean it is rare — but according to the Atlas its share of the commercial catch could be underestimated, because it is probably misidentified as *S. dumerili*. Italian Wikipedia gives ricciola atlantica as its trade name. And for anyone who wants to eat it, FishBase has a note under “threat to humans”: there are reports of ciguatera poisoning. Where and how often, it does not say.

Where the sources disagree

  • How big does it get? FishBase: at most 72.5 cm total length, commonly 40 cm. Spanish and Catalan Wikipedia: 72.5 cm total length. English Wikipedia: at least 48 cm fork length, probably considerably more. Italian Wikipedia: up to 55 cm, adding that it is not clear whether it grows larger. CIESM Atlas: in the Mediterranean on average 65 cm fork length, in the Atlantic up to 55 cm fork length — the Mediterranean average would thus exceed the same source’s Atlantic maximum, and the Atlas follows its own figure with the question of whether standard or total length is meant.
  • How many spines in the first dorsal fin? CIESM Atlas: 7–8. FishBase: 8–9. Italian Wikipedia: 7 or 8 — in the greater amberjack, it says, there are always 7.
  • How many gill rakers? CIESM Atlas: 22–23. Italian Wikipedia: 19–23.
  • What colour is it? CIESM Atlas: adults dark pink. Italian Wikipedia: the coloration is not known with certainty; it is therefore not known whether it can be used to separate it from the greater amberjack.
  • Established or not? CIESM Atlas: establishment success rare. Italian Wikipedia: caught in good numbers off Lampedusa — and because the fish had gonads ready to spawn, it suggests that the species has established itself in the Mediterranean.
  • 1996 or 2000? The map in the CIESM Atlas dates the first Mediterranean record to 2000, and English Wikipedia writes “since 2000”. According to the same Atlas, the fish were reported for August 1996 and September 1997 — 2000 is the year of publication.
  • Which order? Spanish and Catalan Wikipedia as well as GBIF: Perciformes. FishBase and CIESM Atlas: Carangiformes. That is a difference in the state of the classification, not in the species.

Three name traps

  • “Mediterranean amberjack” means two species. GBIF lists this English name (from the Catalogue of Life) for *S. carpenteri*. A 1995 paper by Marino and colleagues cited in the CIESM Atlas, by contrast, uses it in its title for *Seriola dumerili*.
  • “Ricciola atlantica” is no proof of origin. That is what *S. carpenteri* is called in the trade, according to Italian Wikipedia. The name describes the home of the species, not the place where the individual fish was caught: the fish off Lampedusa were caught in the Mediterranean.
  • “Charuteiro” with and without a suffix. In Portuguese, GBIF lists charuteiro-da-Guiné for *S. carpenteri*; charuteiro on its own is listed by GBIF for *S. fasciata*. Alongside these, *S. carpenteri* also has the Portuguese name seriola-do-golfo and the Catalan name sériole del golf — “of the gulf”, without the source saying which one.

Which brings us to the when, where every article in this series ends. With *Seriola carpenteri* the sources give two clues: both records off Lampedusa date from August and September, the CIESM Atlas places the presumed spawning season in the same months — and the species keeps to surface water above 25 °C. On feeding time there is not a word anywhere. Habitat, prey and features are covered above, as far as they are documented. What changes every day are the conditions on your water — StrikeAhead calculates them and tells you when the trip is worth it. And because nobody knows the edges and rules of unfamiliar water from day one, StrikeAhead Pathfinder tells you who to go out with: curated guides and skippers, personally vetted before listing — licence and insurance —, with verified catches instead of promo shots, no paid ranking and, for you as an angler, no booking fee. The app tells you when, Pathfinder who with.