Is it a bird or a fish? It’s a baby tompot blenny, just like Benny the Blenny’s babies, swimming in the plankton.

This video shows tompot blenny larvae like my babies swimming around in the plankton. These ones are around 15mm long and Teresa thinks they look like baby birds because they are flapping their pectoral fins to keep themselves swimming up in the water. They power themselves forwards using their tails too. When my babies first hatched as larvae they had a yolk sac which helped them stay up but that has now all been used up so they flap instead. If you look closely at the video you will see, just under the babies’ bellies, that there are two blackish lines. These are their pelvic fins (equivalent to your legs) that have started to develop. My youngsters at this stage are not showing any signs of growing head tentacles, but these will develop by the time they settle on the seabed as little tompot blennies around 20 mm long in a few weeks time.

Thank you to the National Marine Aquarium Plymouth for their help in getting this video; it is an excellent place to see tompot blennies like Benny the Blenny and lots of other marine life in action.

For wonderful line drawings and descriptions of tompot blenny larvae, see this paper:

Fives, Julie. M. 1986 Blenniidae of the Northern Atlantic (revised)  Fich. Ident. Plancton (172:6pp)


This blog has been written for children on the benny’s blog




Flying about in the plankton, a baby tompot blenny!

Tompot larva NMA 190816 2


Hey, this shows what my tompot blenny babies look like when they have left home, having hatched from those eggs that I’ve been guarding. Swimming among the plankton in the open sea, they are very sleek with gorgeous big eyes and are between 4 and 20 mm long.

When they first hatch they eat very small plant (phyto-) plankton and animal (zoo-) plankton, the youngsters grow quickly and are then able to eat larger plankton. Bigger fish larvae and jellyfish in the plankton are a real danger and my babies have to make smart evasive moves if they see they are about to be grabbed!

If you would like to find out more about plankton visit:

This photo was made possible by the National Marine Aquarium in Plymouth so many thanks to them. Paul, my underwater photographer, would never be able to spot and photograph one of my babies in the wild!