Petromyzon is the jawless fish that lays eggs in freshwater and its ammocoetes larvae after metamorphosis return to the ocean. It belongs to the Class-Cyclostomata of Phylum- Chordata, and subphylum-Vertebrata. ... The eggs hatch in about 3 weeks into minute transparent larvae called ammocoetes.

Does Myxine lay eggs in freshwater?

Petromyzon, Myxine. Petromyzon(the lamprey) belongs to the section Agnatha of the sub-phylum-Vertebrata. They have long, greenish brown, cylindrical body with smooth scaleless, slimy skin, jawless mouth, etc. They lay eggs in freshwater but their ammocoete larvae(lower) after metamorphosis return to the ocean.

Is a sea water fish but it returns to its freshwater home to lay eggs?

Answer: Petromyzon (Lamprey) belongs to the Class- Cyclostomata of Phylum-Chordata. It is a jawless fish which lays eggs in fresh water.