Instituto Dom Luiz

Funder

Organizational Unit

Publications

Characterization of the coccolithophore community off Cabo Verde archipelago, including the Senghor Seamount (Eastern North Atlantic)

Publication . Narciso, Áurea; Javidpour, Jamileh; Chi, Xupeng; Cachão, Mário; Kaufmann, Manfred

A systematic investigation of the extant coccolithophore community around Cabo Verde archipelago was per formed during the cruise MSM49 of RV Maria S. Merian, which took place in the late fall of 2015. The description of the spatial and vertical distributions of coccolithophores was based on a survey performed to the north, east and south of Cabo Verde archipelago, between the surface and 150 m water depth. The total cell densities ob tained for the studied region were relatively low, reaching to a maximum of 30 × 103 cell L− 1 in the upper 50 m over the southeastern slope of the Senghor seamount. Emiliania huxleyi and Gephyrocapsa oceanica were the dominant species, followed by Florisphaera profunda. The coccolithophore distribution off Cabo Verde was essentially explained by relatively warm and nutrient-depleted waters in the region during the surveyed interval, in result of the weaker NE trade winds and the northward migration of the Intertropical Convergence Zone. In these conditions, a notable zonation of coccolithophores along depth was depicted, in consequence of the inferred general well-stratified water column. Four typical depth-related groups were identified: (i) a Shallow oligotrophic (10–30 m), represented by Discosphaera tubifera and Umbellosphaera spp.; (ii) an Intermediate (40–50 m), formed by the three placolith-bearing species E. huxleyi, G. ericsonii and G. oceanica, and by Algir osphaera robusta, Helicosphaera spp., Michaelsarsia spp., Syracosphaera spp. and Umbilicosphaera spp.; (iii) a Deep (60–75 m) with F. profunda, Ophiaster spp., Oolithotus spp. and Reticulofenestra sessilis as typical members; (iv) and The Deepest (>80 m), composed by Gladiolithus flabellatus and Syracosphaera lamina. In addition, high abun dances of G. oceanica related with the Eddy station were attributed to the transport and thriving of the coastal coccolithophore community, dominated by this species, from the African coast towards Cabo Verde.

2021Journal article

Open access

First evidence of ants (Hymenoptera, Formicidae) in the early Pleistocene of Madeira Island (Portugal)

Publication . Marques, Carlos A. Góis; Correia, Pedro; Nel, Andre; Madeira, José; Sequeira, Miguel Menezes de

To be successfully established on oceanic islands, native ants (Hymenoptera: Formicidae) have to migrate from the mainland or from nearby islands, crossing the ocean barriers, to find a suitable habitat. Despite the general interest on oceanic islands biotas, nothing is known about the deep-time migration and settling of native ants in these insular ecosystems. Palaeoentomological studies on oceanic islands that could provide palaeobiological information on Formicidae are scarce. Here, we describe and illustrate the first fossil of an ant from the Macaronesian archipelagos (Atlantic Ocean), based on a partial forewing found within 1.3 Ma (Calabrian, Pleistocene) lacustrine sediments from Madeira Island, Portugal. Although unidentifiable beyond the family level, this fossil record provides a minimum age for the presence of ants in the Madeira archipelago. Palaeoecologically, this record indicates the presence of suitable habitats for ants during the early Pleistocene.

2022Journal article

Open access

Funding agency

Fundação para a Ciência e a Tecnologia

Funding programme

6817 - DCRRNI ID

Funding Award Number

UIDB/50019/2020