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White grouper (Epinephelus aeneus): the grouper that sits over sand and mud

You picture a grouper on rock. This one, according to Italian Wikipedia, sits mainly over sand and mud. *Epinephelus aeneus* is called white grouper in English (FishBase), weißer Zackenbarsch in German (GBIF), cernia bianca in Italian (Italian Wikipedia), mérou blanc in French, cherna de ley in Spanish, garoupa-branca in Portuguese (GBIF), σφυρίδα in Greek, lahoz in Turkish and kirnja bjelica in Croatian (the respective Wikipedia). It grows to 120 cm in length and 25 kg in weight (FishBase), changes sex in the course of its life and is one of the most sought-after food fishes off West Africa. Its home is the eastern Atlantic and the southern Mediterranean — and it is moving north. Here is what the sources know about it, how to recognise it and where they contradict each other.

Bronze in the name, white in everyday speech

It was described by the French naturalist Étienne Geoffroy Saint-Hilaire in 1817 as *Serranus aeneus*, with Egypt as the type locality (English and Slovenian Wikipedia, FishBase). According to FishBase, the genus name *Epinephelus* comes from the Greek *epinephelos*, “cloudy”. The species epithet *aeneus* is Latin and means “of bronze”, “brazen” — and that is exactly what several common names listed by GBIF call it: French mérou bronzé and serran d’airain, Italian cernia bronzina. Most other languages, by contrast, call it white. Both have their reason in what the sources write about its colour — and they do not write the same thing; more on that further down.

How you recognise it

  • Pale lines on the gill cover. Italian Wikipedia calls them the most conspicuous feature: two or three oblique white or bluish lines behind the eye, directed backwards and clearly visible. English Wikipedia counts three or four pale blue or white lines across the gill cover, which can be rather faint in large fish.
  • Elongated body. The body depth is less than the head length and fits 3.0 to 3.6 times into the standard length (FishBase). Compared with the other groupers of the Mediterranean, the body is more elongated and more strongly compressed laterally (Italian Wikipedia).
  • Spines on the preopercle. It is angular and carries three to six large spines at the angle; the lowest one points downwards (English Wikipedia, FishBase).
  • Dark fins with a pale edge. The fins are darker than the body, brownish-purple, with a white or pale margin (English Wikipedia).
  • Juveniles with cross bars. In them, faint dark spots form five indistinct dark cross bars (English Wikipedia). According to Italian Wikipedia the bars are high in contrast in young fish and often barely visible in adults — and in fish living over sand they can disappear completely.
  • Rounded caudal fin (FishBase). In very large fish its margin can become almost straight (Italian Wikipedia).
  • Small scales in thick skin, more than 90 along the lateral line (English Wikipedia).
  • Fin formula: dorsal fin with 10–11 spines and 14–16 soft rays, anal fin with 3 spines and 7–9 soft rays (FishBase).
  • Size: at most 120 cm total length and 25 kg; 60 cm is common (FishBase).

From Angola to Corsica

FishBase describes the range as follows: eastern Atlantic along the west coast of Africa to southern Angola, plus the southern Mediterranean. English Wikipedia has it begin further north, in southern Portugal and southern Spain, and names the southern and eastern Mediterranean. There, according to Italian Wikipedia, it was long considered a species of the southern and eastern coasts only and very rare in Italian waters; since the 2000s, catches are said to have increased in the northern Mediterranean and in the Adriatic, which it now inhabits. FishBase lists the first record from Corsica for 2012, and English Wikipedia names Corsica and Monaco among several new reports from the north. In the Adriatic it is comparatively rare, according to Croatian Wikipedia, and most likely to be found around the Kornati. That individual fish roam far is nothing new: according to English Wikipedia, an older and now invalid name of the species, *Perca robusta*, is based on a specimen from Cornwall in the south-west of England.

Habitat, prey, sex change

  • Depth: 20 to 200 m. It lives on the bottom, in the sea and also in brackish water (FishBase).
  • Bottom: rock or mud and sand (FishBase). Italian Wikipedia weights it differently: mainly sandy and muddy bottoms, also seagrass meadows of *Posidonia oceanica* and *Cymodocea nodosa*, and only more rarely hard bottom.
  • Juveniles in lagoons and estuaries (FishBase). According to French Wikipedia, fish under 30 cm stay mainly close to the coast and then move to depths of 30 to 100 m, with a preference for sandy grounds.
  • Prey: mainly fish. For West African waters FishBase gives 58% fishes, 21% mantis shrimps, 10% crabs and 10% cephalopods.
  • First female, then male. The species is a protogynous hermaphrodite. Females become sexually mature at 50 to 60 cm total length (FishBase), according to English Wikipedia at an age of 5 to 7 years; they turn into males at 10 to 13 years (English and Italian Wikipedia).
  • Millions of eggs. FishBase gives an estimated egg count of 789,436 for a fish of 44 cm standard length and 2.2 kg, up to 12,589,242 for a fish of 87 cm standard length and 12.6 kg.
  • Spawning in summer. Off Tunisia it spawns in June and July, in the Gulf of İskenderun in Turkey from early June to the end of August (English Wikipedia).
  • Migration with the upwelling. Off Senegal it migrates seasonally; this is influenced by the seasonal upwelling of deep water off Senegal and Mauritania (FishBase).
  • Deep in summer, shallower in winter. That is what Greek Wikipedia says, which also names bottoms with stones, mud or algae. There is no second source for this among those read here; the same page gives a maximum age of 17 years.

Sought after, overfished, on a banknote

FishBase lists it as commercially fished, as a gamefish and as a species farmed on an experimental basis; it is sold fresh and smoked, and it is highly valued on the markets of West Africa. It is caught with hook and line and with trawls (English Wikipedia), and according to Italian Wikipedia mainly with trawls and longlines. In Senegal, where it is called thiof, it is said to be the most prestigious fish in the country and to be shown on the back of the 2000 CFA franc note, writes French Wikipedia. Most of the catch there is landed by artisanal fishers; alongside that there is a fishery for export, mainly to Europe (English Wikipedia). The consequence: on the IUCN Red List it is classed as Near Threatened (assessed on 18 November 2016), and overfishing is the greatest threat according to English Wikipedia — even where it is protected, it is said to be poached at night with spear and light. Italian Wikipedia records both side by side: stocks are declining in several parts of the range, while the range itself appears to be growing.

Where the sources contradict each other

  • What colour is it? English Wikipedia: greenish bronze. Italian Wikipedia: ground colour greyish or brownish with broad dark and pale cross bars. Catalan Wikipedia: grey-green. Greek Wikipedia: dark green to copper-coloured, sometimes brown, with four to five dark cross stripes. Croatian and Slovenian Wikipedia: white with five brown cross stripes.
  • Rock or sand? FishBase: rock or mud and sand. Italian Wikipedia: mainly sand and mud, more rarely hard bottom. Turkish Wikipedia: rocky, stony or gravelly spots. Croatian and Slovenian Wikipedia: in holes and crevices in the middle of muddy or sandy bottom.
  • How many lines on the head? English Wikipedia: three or four. Italian Wikipedia: two or three. Catalan Wikipedia: about three.
  • From what depth? FishBase, English, Italian and Turkish Wikipedia: 20 to 200 m. Croatian and Slovenian Wikipedia: 15 to 200 m.
  • When does it change sex? English and Italian Wikipedia: at 10 to 13 years. FishBase: most females at about 9 kg, though there are occasionally smaller males of 3 to 5 kg; for Tunisia 10 to 13 years at 6 to 15 kg and 80 to 110 cm total length. Croatian and Slovenian Wikipedia: at about 10 years and around 8 kg. French Wikipedia: variable, around 75 cm.
  • When does it spawn? English Wikipedia: June and July off Tunisia, early June to the end of August in the Gulf of İskenderun. Turkish Wikipedia: May to June.
  • Does it occur in the Canaries? FishBase: reports from the Canary Islands and from Cape Verde are unsubstantiated. English Wikipedia: its occurrence in the Canaries and in Madeira still needs to be confirmed. French Wikipedia: in the Canaries it is called cherne.
  • 1809 or 1817? Italian Wikipedia dates the original description to 1809, FishBase and English and Slovenian Wikipedia to 1817.
  • Which family? English, Italian, Turkish and Catalan Wikipedia: Serranidae. FishBase and French Wikipedia: Epinephelidae. That is a difference in the state of the systematics, not in the species.

Three traps in the name

  • White, green or bronze — the same fish. For *E. aeneus* GBIF lists Portuguese garoupa-branca and garoupa verde, French mérou blanc and mérou bronzé, Italian cernia bianca and cernia bronzina. The colour in the name does not separate species here.
  • Names without a qualifier say nothing about the species. In the trade it is simply called cernia, according to Italian Wikipedia; GBIF also lists for it French mérou, Serbian kirnja and Turkish lahoz without any qualifier at all. Anyone who reads only such a name does not yet know which grouper is meant.
  • Similar names for similar fish. Greek Wikipedia writes that the σφυρίδα resembles the ροφός and the στήρα — three names for three fish, without the page naming the species at this point. Turkish Wikipedia also calls the lahoz grida, and the orfoz its close relative.

Which brings us to the when, where every article in this series ends. With *Epinephelus aeneus* the sources give three clues: spawning takes place in summer, between May and August depending on the source; off Senegal it migrates with the seasonal upwelling; and according to Greek Wikipedia it sits deep in summer and shallower in winter. 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.