phyto-, phyt-, -phyte

(Greek: a plant; growth; growing in a specified way or place; to produce)

zoophyte (s) (noun), zoophytes (pl)
Any of various invertebrate animals that resemble plants in morphology (form) or mode of life more than that of an animal: The sea anemones, corals, and sponges are considered to be zoophytes.

Sponges, for example, are just barely animals. In fact, they are such a borderline case that until the nineteenth century they were called zoophytes, the animal-plants. Sponges are among the most primitive forms of multicellular animal life.

zoophytology (s) (noun) (no pl)
The branch of zoology concerned with the animals thought to have the aspects or characteristics of plants: Susan decided that she wanted to specialize in zoophytology and be an expert in the research of crinoids, along with corals, sponges, and sea anemones.
zygophyte (s) (noun), zygophytes (pl)
A plant in which reproduction is done by the union of two similar reproductive cells which unite in fertilization: The alga organism is one example of a zygophyte and reproduces itself by the way of zygospores.