Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to breed fish [title] Pick out a healthy adult fish of each sex. [step] In order to breed fish, your first step is to determine their biological sex. Unlike some other animals, this will be trickier than looking for differences in their genitalia.

Ending1: [substeps] This means that only male fish will be conceived in either species. Male fish of the opposite sex will likely be tested to identify difficult breeding possible, but there are specific guidelines included. Ending2: The biological differences between species can vary greatly, but there are a few common traits to look for. Female cichlids, for example, tend to have rounded bodies and less pronounced vents, while males usually display more vibrant coloration and sometimes have a small hump on their heads. Ending3: Traditionally, fish have estrus, a hormone stimulating hormone that gives them the ability to produce sperm. Young males tend to produce semen during those kinds of mating, which is often an early birth. Ending4: It is best to find a fish with a cute face, thin feet, tender flesh, and delicate eyes. [substeps] Poodles are small crayfish with thin flesh, one with triangular heads.

Answer format: ending1/ending2/ending3/ending4