Small-Spotted Catshark: The Predator Science Calls a Dog
Every article in this series answers the same question: how does the angler outwit the predator? With which bait, at what depth, at what time. With the small-spotted catshark the answer begins with an argument about the animal itself — an argument carried inside its own name. Science calls it a dog: its species name is *canicula*, Latin for little dog, and the genus name *Scyliorhinus* goes back to a Greek word for a small dog as well. Yet from Naples to Zagreb, from Istanbul to the Basque country, the same fish is a cat. So the pole of this article is: the predator science calls a dog and half of Europe calls a cat. The fish is *Scyliorhinus canicula* — according to FishBase the most common catshark in the coastal waters of Europe, and therefore the shark an angler in the Mediterranean or the eastern Atlantic is most likely to have on the line.
Twice a dog, once a rasp
The origins of scientific names are recorded by the ETYFish Project, an etymological register of fish names; its family page “Family SCYLIORHINIDAE Gill 1862 (Catsharks)” carries the revision date 7 Nov. 2025. The species name canicula is explained in six words: “diminutive of canis (L.), dog” — a diminutive of the Latin *canis*, dog. The same source gives the reason: “sharks were derogatorily called ‘dogs’ or ‘sea dogs’ in ancient times”. The genus name Scyliorhinus (Blainville 1816) doubles down on it: “scylio-, from skýlion (σκύλιον), small dog or whelp, i.e., a small shark” — from the Greek *skýlion*, a small dog or whelp. The second half, rhinus, is “an ancient name for sharks”, either from *rhinos* (ῥινός), the skin or hide of a beast, or from *rhínē* (ῥίνη), rasp — both, ETYFish says, alluding to a shark's rough skin. On the same page stands the sister species for comparison: *Scyliorhinus stellaris* is “Latin for starry or of the stars, referring to many large and small black and white spots on body” — the starry one.
Dog, cat, red — and in Japan a tiger
How little Europe held to the scholars' dog is shown by the GBIF name list for *Scyliorhinus canicula* (key 2418684, 186 entries). There is a dog camp: English “Lesser spotted dogfish”, “Sandy dogfish”, “Rough hound” and even “Fay dog”; Dutch “Hondshaai”, the dog shark; Polish “Rekinek psi”, the dog sharklet; Greek “Σκυλοψαράκι”, the little dog-fish; Spanish also “Pez perro”. And there is a cat camp, which is larger: German “Kleingefleckter Katzenhai”, Italian “Gattuccio” — little cat — Maltese “Gattarell” and “Gattarell tat-tikek”, the spotted one; Turkish “kedi balığı”, the cat fish; Slovenian “navadna morska mačka”, the common sea cat; Serbian “Morska macka”; Albanian “mace deti” and “mice me pika”; Basque “katuarraina”; Russian “кошачья акула”; Catalan simply “gat”. Even French, which properly belongs to a third camp, carries “Chat marin” and “Gat” as well.
That third camp is the red camp — and it is the only one that says its colour out loud: Danish “Småplettet rødhaj”, Swedish “Småfläckig rödhaj”, Norwegian “Småflekket rødhai”, all three literally the small-spotted red shark, and Finnish “Pistepunahai”, the spot-red-shark. French calls it “Petite roussette”, Spanish “Pintarroja” and “Pitarrosa”, Portuguese “Pata-roxa”. ⚠️ That these Romance names contain a colour word is an observation about the word, not a documented derivation — GBIF supplies names, not etymologies, and this article claims no more. Only the north is explicitly red. Then there are the Celtic names, which go their own way: Welsh “Morgi” and “morgi meiaf”, Scottish Gaelic “morgay”, Irish “An fíogach beag” — and Breton has all three camps at once: “kazh mor” (cat), “chienbrô” (dog) and “ki-rouz” (red). One language, three camps. ⚠️ The Gaelic entry “sporan feannaig” stands in the GBIF list without any explanation; this article does not interpret it. And Japan stands apart entirely: the Japanese Wikipedia opens its article with “ハナカケトラザメ Scyliorhinus canicula” — a name ending in トラザメ, literally tiger shark. Neither dog nor cat.
💣 Four name traps. First, the sister species. The Japanese name “ヨーロッパトラザメ”, the “European catshark”, does not mean this fish but *Scyliorhinus stellaris*. Reach for the European-sounding name and you land on the larger neighbour. Second, “dogfish”. In English the word is not a proper name: it also carries the spurdog, *Squalus acanthias*, which does not even share an order with our fish. When “dogfish” is said on board, the species has not been identified. Third, the cat without a second word. In Croatian *S. canicula* is “mačka bljedica” while the sister species *S. stellaris* is “mačka mrkulja” — both are “mačka”, and the official list carries a collective “mačke” for the whole genus on top. Italian “Gattuccio” and Maltese “Gattarell” face the same problem; only the second word decides. Fourth, Croatian itself. ⚠️ GBIF lists no Croatian name at all for this species — and no Japanese and no Arabic one. The Croatian name used in this article therefore does not come from GBIF but from the Pravilnik o popisu trgovačkih naziva proizvoda ribarstva i akvakulture, the official list of trade names in Narodne novine 6/2023, where “mačka bljedica” stands next to *Scyliorhinus canicula*.
One metre, 3.7 kilos, twelve years
The hard numbers come from FishBase (species page 845), whose main reference for the genus is Soares & De Carvalho (2019). The small-spotted catshark reaches 100 centimetres total length; the common length is 60 centimetres; the maximum published weight is 3.7 kilograms and the maximum reported age twelve years. This is a pocket-sized shark — and that is exactly what makes it a fish you actually catch. FishBase lists its environment as “Marine; demersal”, that is close to the bottom, with a depth range of 10 to 780 metres, “usually 80 - 100 m”. The climate is subtropical, the range 63°N - 3°N, 32°W - 37°E. ⚠️ That climate line runs almost to the equator while the distribution line of the same source stops much earlier: “North Sea (sw coast of Sweden to Copenhagen, Denmark), Northeastern Atlantic Ocean (Ireland, United Kingdom, France, Portugal); Mediterranean Sea (Spain, France, Italy, Tunisia, Algeria, Morocco); nw Africa, close to the Strait of Gibraltar and to the north of Mauritania (20º30'N); including Norwegian Sea.” Both stand there as written; this article does not resolve it.
Sand, gravel, mud — and what it eats there
The sentence that matters most to an angler sits under “Biology” at FishBase and is short: “Most common catshark in coastal waters of Europe. Inhabits continental shelves and uppermost slopes. Found on sandy, coralline, algal, gravel or muddy bottoms.” — the most common catshark in Europe's coastal waters, at home on the shelf and the uppermost slopes, over sandy, coralline, algal, gravel or muddy ground. That is a description of a place, not a footnote: it holds where the bottom is soft, not on the reef. Its prey is listed just as plainly: “benthic invertebrates, including mollusks, crustaceans, small cephalopods, polychaete worms, and small bony fishes” — bottom-living invertebrates, among them molluscs, crustaceans, small cephalopods, polychaete worms and small bony fishes. A predator of the ground, then, which takes fish last. To humans FishBase lists it as “Harmless”.
The purse that hangs on the weed
Unlike most sharks, which bear live young, this one lays eggs. FishBase: “Oviparous, laying paired eggs (one per oviduct) in shallow subtidal areas.” — oviparous, in pairs, one per oviduct, in shallow water below the tide line. The capsule measures 4.9 to 7.0 centimetres long and 1.5 to 3.0 centimetres wide, varying with locality and the size of the female. The embryos “feed solely on yolk” — solely on yolk, with nothing supplied by the mother. And then the sentence that explains this fish's pace: “Fully formed pups hatch after 5-11 months, depending on water temperature.” — five to eleven months, depending on water temperature; newly hatched pups are 8 to 10 centimetres long. ⚠️ Here the source places a contradiction side by side: the egg lies in the shallows, the adult fish usually holds at 80 to 100 metres. Finding egg purses on the weed is not finding where the grown fish stand.
Least Concern — and forbidden in Croatia all the same
FishBase lists the small-spotted catshark as “Least Concern (LC)”, assessed on 31 August 2020, its fishery as “minor commercial” and explicitly “gamefish: yes”. At the same time the same source gives resilience as “Low” with a population doubling time of 4.5 to 14 years and vulnerability as “High (59 of 100)”. ⚠️ Common and slow at once — both stand side by side. And then there are countries that have turned this into a rule. Croatia lists it in the Pravilnik o sportskom i rekreacijskom ribolovu na moru, Narodne novine 48/2026, in force since 1 June 2026, in Prilog 1, Tablica 3 — the “Popis vrsta riba i drugih morskih organizama za koje je zabranjen ulov”, the list of species whose capture is forbidden and whose accidental catch and release must be recorded. It contains “mačka bljedica — Scyliorhinus canicula”, “mačka mrkulja — Scyliorhinus stellaris” and “mačke — Scyliorhinus spp.”, the whole genus. How to handle one is set out in Članak 8, stavak 11 of the same regulation: “Ribolovac je prije izvlačenja iz mora dužan pustiti jedinku živu i neozlijeđenu kad god je to moguće” — the angler is obliged to release the animal alive and uninjured before lifting it out of the sea, whenever that is possible. ⚠️ This is a cited passage, not legal advice, and it applies to Croatia; rules differ by country and change. The competent authority decides. The point for the angler is a different one: a global status of “Least Concern” tells you nothing about what is allowed at your water.
What that means on the water
- Soft ground, not reef. FishBase names sandy, coralline, algal, gravel or muddy bottoms on the shelf and uppermost slope. Know the ground and you know the area — StrikeAhead shows you depth and conditions for your spot.
- Eighty to a hundred metres is the rule, ten to 780 the span. “Usually 80 - 100 m” is the source's wording, not a rule of thumb from the harbour.
- A pocket-sized shark. One metre maximum length, 3.7 kilos maximum weight: catching a catshark is not catching a monster — and FishBase lists it as harmless.
- It grazes the bottom. Molluscs, crustaceans, small cephalopods, polychaete worms, and only then small fishes. None of the sources read says which bait size or method catches; this article promises none.
- The egg purse is not a find at the fishing mark. Laid in the shallows, held in deep water. Five to eleven months to hatching, depending on water temperature.
- Slow to recover. Resilience “Low”, doubling time 4.5 to 14 years, vulnerability “High (59 of 100)” — an argument for careful handling and for release, even where nobody demands it.
- Check the rules yourself. In Croatia the whole genus sits on the prohibited list, together with the duty to release it while still in the water. Elsewhere other rules apply. Minimum sizes, bag limits and closed seasons change — the competent authority decides; this is not legal advice.
- Ask for the second word. “Gattuccio”, “mačka”, “dogfish”, “Gattarell” — none of these names identifies the species on its own. Only the epithet separates it from its sister.
The small-spotted catshark is the predator science calls a dog: a Latin little dog in the species name, a Greek whelp in the genus — and a continent that never went along with it and says cat, in the north red shark, in Japan tiger. Behind the names sits a metre-long shark that lives over soft ground, hangs its eggs in purses in the shallows, and is bycatch in one country and a prohibited species in the next. StrikeAhead reads conditions and depth and learns from your catches; the app tells you when it is worth going, and StrikeAhead Pathfinder tells you who to go out with on unfamiliar water — curated, personally checked, with verified catches instead of stock photos, no paid ranking, and no booking fee for you as an angler.