Not sure if this is a cockerel.

[Ol Grey Mare]

A dom is a barred chicken, they look a lot like that rooster in the picture, the Barred Rocks are a perfect example of a dom

Dominique and barred rock are two different breeds, neither is an example of the other.

 

[Gray Farms]

Yes your Marans is a cockerel. Not a Barred Rock or Dominique.

 

[drumstick diva]

x2 Gray Farms

 

[RoostersAreAwesome]

Barred rock rooster.

Not a barred Rock, wrong leg color.

Yes, he is a rooster.

 

[Zeke2216]

Not a barred Rock, wrong leg color.

Yes, he is a rooster.

He's a Silver Cuckoo Marans.