A Dad’s duties

Tompot blenny, single with eggs 1

Here, I’m using my pectoral (shoulder) fins to fan water over Belinda’s developing eggs and keep them healthy. I also have a special gland near my tail that releases important stuff to keep bugs from growing on the eggs. Female tompot blennies like Belinda take care to lay their eggs in a single layer that makes it easy for me to give them all a good wipe over.

Since Belinda’s visit, two other female tompot blennies (let’s call them Barbara and Brenda) have been attracted by my smelly messages (pheromones) and have been flirting just outside my home at different times. I’ve encouraged them in and they have laid their eggs next to Belinda’s. I fertilised them straight away, as I need to make sure I’m their Dad. I have to be on my guard because lots of animals would love to eat my eggs. I can’t leave them unguarded for more than a few moments so I have to grab my own food very quickly!

Guarding my eggs from an edible crab

Tompot blenny RL 1227 93

Now I’ve got eggs to care for, I need to keep intruders away. This edible crab is too close and I’m concerned he wants to use those big claws to pick and eat my youngsters developing in their eggs. As you can see, I’m biting and pushing his leg to scare him off. He’s slow on the uptake so it can take a while but eventually he will get the message and shuffle off. Meanwhile, he is protecting his antennae, eyes and mouth from my attacks.

The velvet swimming crabs can be more difficult to chase away, as they like a fight. I use a different tactic with them because they are fast and have sharp claws. I harass them by darting in quickly so they don’t have time to nip me. I’m clever as well as very bossy!

Becoming a Dad

Tompot pair in crevice, S Devon 1

The reason I fought to keep my territory in March was so that I have a safe place to raise my family. In April, I got my crevice ready to become a nursery by cleaning the floor and ceiling. I then released some special chemicals (called pheromones) from glands near my tail and wafted them into the surrounding seawater. This was to tell the local female tompot blennies that my home was ready for them to lay their eggs. The first female to visit, let’s call her ‘Belinda’, came bustling up and posed at the front of my crevice. I checked her out, liked what I saw and then invited her in. We got to know each other as I gave her a few pecks on the cheek and a gentle nudge. She had a good look round my home and it must have pleased her because she laid a batch of beautiful purple eggs on the floor of my crevice. I fertilised her eggs quickly. I’m going to be a Dad!!

Territorial disputes – mouth fighting

C Paul Naylor

Now the introductions are over, I will bring you up to date with what I’m up to. I spent most of the winter tucked up deep inside my crevice home. At the end of March, with the sea getting a little warmer, I got more active. I’m not the only tompot blenny on my reef and my male rivals started challenging me to take over my home and make it their territory.

A younger male came and tried to chase me out of my home. As you can see from the photograph above, we both stood our ground for a while and sized each other up. I opened my mouth in a threatening way and showed him my teeth and, when he didn’t back off, I darted at him and gave him a bite on his lip. He tried the same back and this is called ‘mouth fighting’. I was better at dodging his bites and managed to land a few nasty nips with my sharp comb-like teeth. He backed off and I showed that I’m the boss of my territory!

Tompot blennies like me, live all around the UK

20150604 004 BOB Tompot blenny distribution map from NBN Gateway 20052015


I’m a pretty successful coastal fish and can generally be found anywhere from just below the low tide mark down to 30 metres deep where there is suitable habitat. I need a cosy hole or crevice to live in and this can be in a rocky reef, under a boulder or in something man-made like a pier or ship-wreck; I’m easily pleased!

I want to show you where fish like me, tompot blennies, have been seen around Britain. This map shows it perfectly, thank you National Biodiversity Network Gateway website and thanks to the people who recorded their sightings of tompot blennies around Britain and Ireland. data.nbn.org.uk

Did you know that if you want to know where you can find a strawberry anemone, a spiny starfish (or even the strange animals and plants that live on land) you can use the NBN Gateway website to find out?