What a mackerel tabby cat is, and how to spot one

The short answer

A mackerel tabby is a cat wearing the striped version of the tabby coat. The Cat Fanciers' Association counts four tabby patterns: mackerel, classic, spotted and ticked. Mackerel is the most common of them, the one where "the stripes are narrow and run parallel to one another like the bones of a fish." The fish is where the name came from.

So the phrase describes markings. A mackerel tabby can be a pedigree Maine Coon, a Bengal, or a cat who turned up in your garage with no paperwork and no intention of getting any. The pattern says nothing about breed, size, temperament or price.

How to tell a mackerel from the other three

CFA describes the mackerel coat as "dense, narrow pencilings," with legs "barred with bracelets coming up to meet the body markings" and a tail "barred with tail rings." Stripes down the flanks, bands around the legs, rings along the tail.

The other three read differently at a glance:

• Classic, also called blotched: "elaborate swirls on the sides and butterflies over the shoulders."
• Spotted: the same stripes or swirls, broken into spots. Ocicats are the usual example.
• Ticked: almost no body pattern at all. The banding sits on each hair, with barring left on the legs and tail. Abyssinians are the standard case.

All four carry the same forehead marking. CFA calls the tabby "M" the characteristic marking on the forehead of every tabby-patterned cat.

The stripes go all the way down to the hair

Look closely at the pale ground colour of a tabby and it breaks up. CFA calls that ground pattern agouti, "the universal camouflage pattern found in several mammals, including cats, mice, rabbits, and squirrels," in which each hair carries "alternating bands of yellow and black."

That camouflage does not switch off indoors. A striped cat lying on dark hardwood at three in the morning is genuinely hard to find.

One gene separates stripes from swirls

A Stanford-led team worked out which gene in 2012. They sequenced a gene they named Taqpep in more than 350 cats across 24 breeds. All 58 blotched tabbies in the study carried mutations in both copies of it. All 51 mackerel tabbies carried at least one unmutated copy.

Two broken copies give you swirls. One working copy gives you stripes. As the team put it: "Mutation of a single gene causes stripes to become blotches, and spots to become stripes."

The same gene turns up in big cats. The team sampled a king cheetah, the rare variety whose spots run together into stripes, and found a Taqpep mutation in him too. The protein the gene makes can be cut loose from the cell membrane to drift through the fluid around it. That ability to float free is central to reaction diffusion, an idea Alan Turing published in 1952 to explain how evenly spaced stripes and spots can come out of randomness.

Which pattern came first

The mackerel stripe is the form without the mutation, so the striped coat is the older look.

Cat history points the same way from a different direction. A 2017 study in Nature Ecology & Evolution read DNA from ancient cat remains and found that a coat-colour variant reached high frequency only after the Middle Ages, which suggests "directed breeding of cats occurred later than with most other domesticated animals."

People got around to breeding cats for their looks long after they had done it to everything else on the farm. Cats mostly got fed.

Which brings us to a twenty-five-pound one

Slug Cat is the grey-and-black striped house cat in the Atomic Critters cast. Our character notes list her species as "cat." She would accept that entry. A tourist left her at Sunrise Sanctuary as a kitten in 2013, and she has run the place by occupancy ever since. Before anybody called her Slug Cat, the file just said Tabby.

Field note: tabby stripes are camouflage. Slug Cat uses hers in the middle of a sunlit footbridge, at twenty-five pounds, directly in the path of everyone who has somewhere to be.

If you want to keep going

Her shirts and hoodies live in the Slug Cat collection, and the women's tee comes in a natural version for anyone who prefers their tabby without the antennae.

If you came here for cats and are leaving faintly curious about why one of them has antennae at all, the Atomic Critters Universe page introduces the rest of the cast. Start Here opens the graphic novel at page one.