10 surprising fishy facts
1. How many fish?
There are an estimated 20,000 species of fish, though the number could be larger. However, the range that we actually eat in the UK is small – our favourites are salmon followed by tuna, cod and haddock.
2. Which fish to eat?
All kinds of edible fish – white fish like plaice, cod or hake or oily fish like trout, salmon or sardines – can be included within a healthy Mediterranean style diet. Baked, grilled or poached in water or a stew are healthier options than going for deep fried or pastry covered fish dishes.
3. Which fish swim upright?
The seahorse is the only fish that swims upright. It can move each of its eyes separately, so one moves forwards while the other one moves backwards.
4. How much oily fish?
At the moment our intake of oily fish is low – we eat about a third of a portion per week, on average, instead of the one portion that is recommended. The omega-3 fats found in fish are some of the essential fatty acids we need to include in our diet for our bodies to function properly. They have also been associated with other health benefits, including in the prevention of coronary heart disease. White fish contain some omega-3, but at much lower levels than in oily fish.
5. Should I take omega-3 supplements?
You don’t need to take omega-3 fish oil (the kind of fat found in oily fish) capsules, or foods supplemented with omega-3. It’s more important to have a healthy, balanced diet, particularly a Mediterranean style diet.
6. Fresh tuna or tinned?
Fresh tuna is a source of omega-3 fats, but tinned is not – the oils are removed during processing. Other tinned oily fish like salmon, pilchards and sardines still contain omega-3 even after the canning process – they make a good option on wholegrain toast or in a sandwich with some salad for a quick lunch.
7. The most revolting fish?
The hagfish (myxine glutinosa) has no eyes and no jaws but can produce huge amounts of slime – enough in one minute to fill a bucket.
8. Should I eat shellfish?
Shellfish like prawns (pictured) contain cholesterol. However, as with eggs, it’s the saturated fat that we consume that is likely to have more of an impact on our cholesterol levels. So you can enjoy shellfish as part of a balanced diet – just go easy on the garlic butter or mayonnaise that might come with them.
9. Do fish have eyelids?
Sharks are the only fish to have eyelids.
10. Why the Mediterranean diet?
The Mediterranean-style diet which includes more fish and less meat has been associated with a reduced risk of heart attack, type 2 diabetes and obesity.