Protocercal is a coordinate term of heterocercal.

As adjectives the difference between protocercal and heterocercal

is that protocercal is (zoology) having a caudal fin extending around the end of the vertebral column, like that which is first formed in the embryo of fishes; diphycercal while heterocercal is (ichthyology) of a fish's tail, such that the vertebral column bends and extends upwards into the upper lobe of the tail, making it larger than the lower lobe; as in sharks, rays, and skates.

As nouns the difference between sturgeon and sterlet

is that sturgeon is any marine or freshwater fish of the family Acipenseridae that are prized for their roe and are endemic to temperate seas and rivers of the northern hemisphere, especially central Eurasia while sterlet is a smaller, common Eurasian sturgeon, of the species species: Acipenser ruthenus.

As a verb systematizing

is present participle of systematize.

As a noun systematology is

the science or study of systematizing.

Limer is a alternative form of lymer.

As nouns the difference between lymer and limer

is that lymer is obsolete form of lang=en|limer while limer is a kind of dog kept on a lead; a bloodhound; a mongrel.

Heapy is a synonym of cumulose.

As adjectives the difference between cumulose and heapy

is that cumulose is full of heaps while heapy is having lots of heaps or piles.

Heapily is a derived term of heapy.

As an adverb heapily

is in a heapy manner.

As an adjective heapy is

having lots of heaps or piles.

Heapiness is a derived term of heapy.

As a noun heapiness

is the state or quality of being heapy.

As an adjective heapy is

having lots of heaps or piles.

Retroviral is a derived term of retrovirus.

As a noun retrovirus

is a virus that has a genome consisting of RNA.

As an adjective retroviral is

of or pertaining to a retrovirus.

Retroviral is a derived term of antiretroviral.

As adjectives the difference between antiretroviral and retroviral

is that antiretroviral is that combats infection by retroviruses while retroviral is of or pertaining to a retrovirus.

As a noun antiretroviral

is an agent that combats retroviruses.

As nouns the difference between sheep and sheepy

is that sheep is a woolly ruminant of the genus ovis while sheepy is (childish|or|endearing) sheep.

As an adjective sheepy is

resembling a sheep, except in sheepish behavior.