Fiddler ray snouts are translucent. The fiddler rays are also distinguished from other guitarfishes in that the anterior nasal flaps of their nostrils are expanded backwards and fused together into a nasal curtain that reaches the mouth. Fiddler rays feed on bottoms shellfish, crabs, and worms, which they crush between their jaws. The eastern fiddler ray is known to scavenge from fish traps. Like other guitarfishes, fiddler rays are ovoviviparous. The egg capsules of the southern fiddler ray are reported to be golden in colour, containing three embryos each. It gives birth to litters of four to six young per breeding cycle.
Hermit (hummingbird) very decurved bills. Many species, including the rufous-breasted hermit, also use the heliconias for nesting, attaching their conical nest to the underside of one of the plant's broad leaves. The taxonomy of some groups has changed significantly in recent years. Apart from those issues discussed at "Phaethornis", a taxonomic problem occurs with the "Threnetes leucurus"/"T. niger" complex. Schuchmann & Hinkelmann (1999) considered the sooty barbthroat a melanistic variant of the "T. leucurus", but as it was described first, its scientific name was adopted for the entire species; pale-tailed barbthroat ("T. niger"). This, however, has not been accepted by all authorities,