Student Mentor Mixer Riddles

Riddle 1

My first is in jackass but not in carp

My second is in Gobiidae and also in old wife

My third in Platycephalus but not trumpeter

My forth is in littoral zone not in trutta

My fifth in land but not in lake

My sixth in coral cod and orange roughy 

My seventh in oarfish as well as giant herring

My last is in stingray but not triggerfish

Who am I? 

Riddle 2 

Islands in the stream

That is what we are

No one in-between

How can we be wrong

 

I share something with a singer that covered this song. 

What is my name and in who is my closest Australian relative?