| 2. |
- Maasri, Alain, et al.
(author)
-
A global agenda for advancing freshwater biodiversity research
- 2022
-
In: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 25:2, s. 255-263
-
Journal article (peer-reviewed)abstract
- Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.
|
|
| 3. |
- Dijkstra, Peter D., et al.
(author)
-
Divergent hormonal responses to social competition in closely related species of haplochromine cichlid fish
- 2012
-
In: Hormones and Behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 61:4, s. 518-526
-
Journal article (peer-reviewed)abstract
- The diverse cichlid species flocks of the East African lakes provide a classical example of adaptive radiation. Territorial aggression is thought to influence the evolution of phenotypic diversity in this system. Most vertebrates mount hormonal (androgen, glucocorticoid) responses to a territorial challenge. These hormones, in turn, influence behavior and multiple aspects of physiology and morphology. Examining variation in competition-induced hormone secretion patterns is thus fundamental to an understanding of the mechanisms of phenotypic diversification. We test here the hypothesis that diversification in male aggression has been accompanied by differentiation in steroid hormone levels. We studied two pairs of sibling species from Lake Victoria belonging to the genera Pundamilia and Mbipia. The two genera are ecologically differentiated, while sibling species pairs differ mainly in male color patterns. We found that aggression directed toward conspecific males varied between species and across genera: Pundamilia nyererei males were more aggressive than Pundamilia pundamilia males, and Mbipia mbipi males were more aggressive than Mbipia lutea males. Males of both genera exhibited comparable attack rates during acute exposure to a novel conspecific intruder, while Mbipia males were more aggressive than Pundamilia males during continuous exposure to a conspecific rival, consistent with the genus difference in feeding ecology. Variation in aggressiveness between genera, but not between sibling species, was reflected in androgen levels. We further found that M. mbipi displayed lower levels of cortisol than M. lutea. Our results suggest that concerted divergence in hormones and behavior might play an important role in the rapid speciation of cichlid fishes. (C) 2012 Elsevier Inc. All rights reserved.
|
|
