Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

the cyclostomes (or cyclostomata) are the lamprey and hagfish.
cyclostome

the channel catfish (scientific name:"ictalurus punctatus"), also called the channel cat, is a species of catfish.
channel catfish

the social democratic party of germany (german sozialdemokratische partei deutschlands or spd) is the oldest political party in germany that still exists, having been formed on 23 may 1863.

social democratic party of germany