Nålmålers

Nålmålers are small, often colorful, marine invertebrates belonging to the phylum Cnidaria. They are characterized by their stinging cells, known as cnidocytes, which they use for defense and capturing prey. These stinging cells are typically located on their tentacles. Nålmålers are a diverse group, with many species exhibiting a range of forms, from free-swimming jellyfish-like medusae to sessile polyp forms.

The life cycle of nålmålers often involves both a polyp and a medusa stage, though the prominence of each stage can vary significantly between species. Reproduction can be asexual, through budding or fission, or sexual, with the release of eggs and sperm. Diet generally consists of small planktonic organisms, fish larvae, or other small invertebrates.

Nålmålers are found in marine environments worldwide, inhabiting a variety of habitats from shallow coastal waters to the deep sea. Some species are bioluminescent, producing light through chemical reactions. While many nålmålers are harmless to humans, a few species possess potent venom that can cause significant pain or injury upon contact. Their ecological role includes being both predators and prey within the marine food web.