Halodule genus in Brazil: A new growth form

Abstract

Here, we report the presence and features of a new growth form of the seagrass Halodule found on the Brazilian coast. In August and October of 2014, Halodule samples were collected in the Timonha-Ubatuba Estuarine Complex, in the semiarid coast of Brazil. Using morphological identification tools available for the genus, we verified that specimens collected were not the traditional Halodule described for the Brazilian coast; instead, they were similar to H. beaudettei. The plant presented blade apex with a distinct central tooth and two lateral teeth. Its leaves were wider and longer than other Halodule species; both those found in the same and other sites along the Brazilian coast. Based on coloration and morphological characters, populations of the H. beaudettei Brazilian growth form can be easily distinguished from the cohabitant H. wrightii populations. These findings may extend the southern habitat for H. beaudettei in the Americas by more than 5500km and highlights the need to discuss the number of seagrass species present at the Brazilian coast.