LOGIN

RSS Facebook Twitter YouTube
GLOSSARY       

SEARCHGLOSSARY

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

PROFILESEARCH

Avatar

Please consider registering
guest

sp_LogInOut Log In sp_Registration Register

Register | Lost password?
Advanced Search

— Forum Scope —




— Match —





— Forum Options —





 

Minimum search word length is 4 characters - maximum search word length is 84 characters

sp_Feed Topic RSS sp_TopicIcon
Biological Journal of the Linnean Society
January 7, 2014
3:40 pm
Avatar
Matt
Málaga, Spain
Admin
Forum Posts: 8239
Member Since:
June 13, 2011
sp_UserOfflineSmall Offline

One cost of being gold: selective predation and implications for the maintenance of the Midas cichlid colour polymorphism (Perciformes: Cichlidae)

In the colour-polymorphic Midas cichlid fish species complex (Amphilophus citrinellus spp.), gold morphs occur at much lower frequencies (< 10%) than dark individuals. This might be surprising because gold coloration is dominant and coded for by a single Mendelian locus. Furthermore, gold individuals are considered to be competitively advantaged over dark ones because they grow faster and win aggressive encounters more often compared to dark individuals of equal size. However, one might expect a cost of being gold in terms of natural selection as a result of predation. We tested whether the Jaguar cichlid (Parachromis managuensis), a major fish predator of Midas cichlids, preys differentially on colour variants of goldfish (Carassius auratus auratus), which were used as a proxy for Midas cichlids because of their similarity in colour. Size-matched pairs of prey fish (gold and dark) were offered to the predator and the time until the fish were attacked was recorded. The gold morph was attacked first more often (approximately 70%) but not faster than the dark morph. This suggests that the predator perceives the gold individual first, and/or that the predator exhibits a preference or higher motivation to attack the gold prey fish. The increased risk of predation of gold prey fish suggests for the Midas cichlid system that being gold may carry significant costs in terms of natural selection as a result of its major piscivorous predator

 

Reduced genetic variation and strong genetic population structure in the freshwater killifish Valencia letourneuxi (Valenciidae) based on nuclear and mitochondrial markers

The genetic variation of the critically endangered Corfu killifish (Valencia letourneuxi), an endemic freshwater fish species of the western Balkans, was assessed for nine populations sampled in eight water systems in western continental Greece, the Peloponnese and the Ionian Island of Corfu, using mitochondrial and microsatellite markers. The analyses were based on data from three mtDNA regions (D-loop, COI and 16S rRNA sequences) and 14 microsatellite loci. Samples from the congeneric species Valencia hispanica and the phylogenetically closely related species Aphanius fasciatus were also used in the study as outgroups. Both the mitochondrial and the microsatellite analyses revealed three distinct population groupings associated with the geographical distribution of the populations: one southern group occupying rivers draining to the Patraikos Gulf, the second one including the populations flowing into the Amvrakikos Gulf and the third, more northern group, including the other populations from rivers in Corfu Island and Epirus flowing into the Ionian Sea. Within these groupings there is limited genetic differentiation between populations; in addition, there is reduced intrapopulation genetic variation, evidenced by low heterozygosity values, number of alleles and haplotype diversity. In terms of taxonomic implications and appropriate management actions for conservation, our data suggest that the major population groups should be regarded at least as three distinct conservation units (CUs), with translocation and restocking actions to take place only within the geographical range of the CU concerned

Cake or death?
Forum Timezone: Europe/Paris

Most Users Ever Online: 246

Currently Online:
1 Guest(s)

Currently Browsing this Page:
1 Guest(s)

Devices in use: Desktop (1)

Top Posters:

Stefan: 1567

Plaamoo: 1257

mikev: 1134

Malti: 1099

Mark Duffill: 1012

Member Stats:

Guest Posters: 0

Members: 30513

Moderators: 0

Admins: 2

Forum Stats:

Groups: 4

Forums: 10

Topics: 4603

Posts: 36641

Newest Members: vandviden, drwonga, dg, Jamieson22, FraziersAquarium

Administrators: dunc: 1323, Matt: 8239