Antifouling activity of twelve demosponges from Brazil

Benthic marine organisms are constantly exposed to fouling, which is harmful to most host species. Thus, the production of secondary metabolites containing antifouling properties is an important ecological advantage for sessile organisms and may also provide leading compounds for the development of antifouling paints. High antifouling potential of sponges has been demonstrated in the Indian and Pacific oceans and in the Caribbean and Mediterranean seas. Brazilian sponges remain understudied concerning antifouling activities. Only two scientific articles reported this activity in sponges of Brazil. The objective of this study was to test crude extracts of twelve species of sponges from Brazil against the attachment of the mussel Perna perna through laboratorial assays, and highlight promising species for future studies. The species Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra, and Tethya maza were frozen and freeze-dried before extraction with acetone or dichloromethane. The crude extract of four species significantly inhibited the attachment of byssus: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), and Hymeniacidon heliophila (p = 0.00003). These species, specially, should be the target of future studies to detail the substances involved in the ability antifouling well as to define its amplitude of action.

The value of cytological criteria in distinguishing sponges at the species level: the example of the genus Polymastia

We examined the value of using cytological criteria for sponge taxonomy within the well-defined genus Polymastia and redescribe the species Polymastia janeirensis comb.nov. Comparison of the anatomical, morphological, and skeletal characteristics of P. janeirensis with those of the 17 other known Atlantic species demonstrated that P. janeirensis is closely related to P. agglutinans and P. mammillaris. The study confirmed that the close relationship between P. janeirensis and P. mammillaris can also be recognized at the cytological level. We conclude that cytological criteria can be used for the identification of sponges at the species level, and that these criteria may provide useful information about phylogenetic relationships among sponges belonging to genera with many species and a wide geographical distribution.