Hydrozoa (hydrozoans; from Ancient Greek ὕδωρ (húdōr) 'water' and ζῷον (zôion) 'animal') is a taxonomic class of individually very small, predatory animals...

Schuchert P, ed. (2012). "Turritopsis dorhnii (Weissmann, 1883)". World Hydrozoa database. World Register of Marine Species. Retrieved November 29, 2012...

Cnidaria, and is often considered a subphylum. It includes the classes Hydrozoa, Scyphozoa, Staurozoa and Cubozoa, and possibly the parasitic Polypodiozoa...

Siphonophorae (from Greek siphōn 'tube' + pherein 'to bear') is an order within Hydrozoa, which is a class of marine organisms within the phylum Cnidaria. According...

animal species that have both polyp and medusa stages in their life cycle. Hydrozoa belongs to the phylum Cnidaria, which are aquatic (mainly marine) organisms...

classification Domain: Eukaryota Kingdom: Animalia Phylum: Cnidaria Class: Hydrozoa Order: Anthoathecata Family: Corynidae Genus: Coryne Gaertner, 1774 Species...

classification Domain: Eukaryota Kingdom: Animalia Phylum: Cnidaria Class: Hydrozoa Order: Anthoathecata Family: Bougainvilliidae Genus: Bougainvillia Lesson...

sea pens); swimming Scyphozoa (jellyfish); Cubozoa (box jellies); and Hydrozoa (a diverse group that includes all the freshwater cnidarians as well as...

related more closely to scyphozoan jellyfish than either are to the Hydrozoa. Hydrozoa medusae also have tetra-radial symmetry, nearly always have a velum...

while the medusa stage is a singular, planktonic organism. Generally in hydrozoa the medusa develops from the asexual budding of the polyp and the polyp...