Evaluation of Chemical Defense and Chemical Diversity in the Exotic Bryozoan Amathia verticillata

Abstract

The present investigation tests the effects against feeding by fishes of crude extracts obtained from eleven distinct populations of the bryozoan Amathia verticillata, an invasive species found globally in tropical to warm-temperate waters. Investigation of extracts from 11 populations of A. verticillata led to the identification and quantification of the known indole alkaloid 2,5,6-tribromo-N-methylgramine and isolation and identification of the new indole alkaloid, 2,6-dibromo-N-methylgramine. One extract of A. verticillata from Brazil significantly deterred feeding, while other extracts of A. verticillata from Florida significantly stimulated feeding by fishes, in field assays performed in Brazil. The same extracts of Florida samples showed variable effects on feeding, ranging from attraction to deterrence, in assays carried out in Florida. The absence of broad chemical defenses against feeding by fish suggests that the establishment of A. verticillata as an invasive species into new areas may be due to reasons other than defensive chemistry.

Marine natural products

“…Culture in the presence of cobalt induced production of antibiotic polyenes 538-541. 224 Other Penicillium strains produced indole diterpenoids 542- 238 Culture of Scedosporium apiospermum on media supplemented with various amino acids induced production of a range of alkaloids including scedapins A-G (599-605) and scequinadolines A-G (606)(607)(608)(609)(610)(611)(612). Of these, scedapin C 601 and scequinadoline D 609 displayed signicant activity against hepatitis C virus (HCV).…”

“…Few compounds are usually reported from this understudied phylum and in fact, in 2016, no new metabolites were reported but in 2017 there was a remarkable upswing, with 16 new compounds isolated. The indole alkaloid, 2,6-dibromo-Nmethylgramine 1375 was obtained from Amathia verticillata, 611 while sterol 1376 and ceramides 1377, 1378 were isolated from Cryptosula pallasiana. 612 Schizomavella mamillata was the source of 5-alkylresorcinol derivatives, schizols A-F 1379-1384, with 1379 and 1380 possessing high radical scavenging activity.…”

First record of the non-indigenous bryozoan Amathia verticillata (delle Chiaje, 1822) (Bryozoa, Vesiculariidae) in the southern Mexican Pacific

“…The final characteristic that could be an advantage for the dispersal and settlement of Amathia verticillata is the production of secondary metabolites. This species produces bromo-alkaloids, which prevent the settlement of other fouling organisms (Winston 1995, Santos et al 2017. Some authors (Winston 1995, Marchini et al 2015 establish that these compounds might even discourage predators or provide protection against viral or bacterial diseases.…”

“…This is important because it is still unclear if A. verticillata is a widespread species or a complex of cryptic species (Nascimento 2015, Waeschenbach et al 2015. To date, only few studies (Nascimento 2015, Waeschenbach et al 2015, Miralles et al 2016, Santos et al 2017 have confirmed the identity of the bryozoan from 6 countries (Australia, Brazil, Italy, Mexico, Spain, and the USA) using molecular analyses. Applying this type of approach to Mexican specimens will not only allow a more accurate identification, but also give evidence on the introduction and dispersal of this species in the country.…”