The actual design isn't bad.
But the execution could be a lot better.

For this type of thing, the lines should be a bit thicker.
Some of the lines need a lot of work, too.
Specifically in the gills.
The lines on the tail are kind of rough.

And the lighter blue eyes throw it off a bit, with the darker blue in there, too.
I would just make the eyes white.

Illustrated wrote The actual design isn't bad.
But the execution could be a lot better.

For this type of thing, the lines should be a bit thicker.
Some of the lines need a lot of work, too.
Specifically in the gills.
The lines on the tail are kind of rough.

And the lighter blue eyes throw it off a bit, with the darker blue in there, too.
I would just make the eyes white.

Thank you for this i hope to get some better work out there

I think this is great, especially for someone who has recently come to terms with the pen tool...

All I can say on the improvements side of things, is be abit more careful with your lines. I have noticed a few lines are abit 'messy' as they extend longer past other lines if you understand what i'm saying?