ðeɪ ɑːɹ smˈɔːl fˈɪʃ, ˈɔːl lˈɛs ðɐn ɪn ɐdˈʌlt lˈɛŋθ, ænd ɑːɹ dɪstˈɪŋɡwɪʃt baɪ ðɛɹ hɐbˈɪtʃuːəl hˈɛddˌaʊn pˈɔstʃɚz.
They are small fish, all less than  in adult length, and are distinguished by their habitual head-down postures.