caa a22 4500 445296631 CHVBK 20180317142544.0 cr unu---uuuuu 170323e20101201xx s 000 0 eng 10.1134/S0032945210110123 doi (NATIONALLICENCE)springer-10.1134/S0032945210110123 Alyan Sofyan Department of Biology, United Arab Emirates University, P.O. Box 17551, Al Ain, United Arab Emirates aut Male Betta splendends are equally aggressive toward neighbors and strangers [Elektronische Daten] [Sofyan Alyan] Male Siamese fighting fish, Betta splendens, are known for their ferociousness when defending their territories against male or female conspecific intruders. The aim of this study was to investigate whether this species exhibits the dear enemy phenomenon, where territorial males would be less aggressive toward neighbors with already established territories than toward complete stranger males. In experiment 1, a male Betta was placed in an aquarium. A second male was placed in a glass jar that was fitted in one corner of the aquarium. After 24 h, a cover was placed around the jar, and then removed after 1 h. Alternatively, the jar male was replaced with a different male of a different color while the jar was covered. The frequency and duration of opercular expansion by the aquarium male were recorded. In experiment 2, two male Bettas were placed, each in a half of a large aquarium that was equally divided by a clear, perforated Plexiglas divider. After 24 h, one male (intruder) was transferred into the other male's (resident) half. In another variation of the experiment, the intruder was a stranger male Betta that the resident male had never encountered before. The opercular expansion and duration were scored for the resident male. The results indicated that male Siamese fish reacted similarly to familiar and stranger males. This lack of dear enemy effect in Siamese fish could be due to an inability to discriminate between neighboring males and non-neighboring males. Alternatively, territorial males could be equally aggressive to all intruders because all intruders represent equal danger. Pleiades Publishing, Ltd., 2010 Siamese fighting fish nationallicence dear enemy nationallicence conspecific discrimination nationallicence Journal of Ichthyology SP MAIK Nauka/Interperiodica 50/11(2010-12-01), 1066-1069 0032-9452 50:11<1066 2010 50 11489 https://doi.org/10.1134/S0032945210110123 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S0032945210110123 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Alyan Sofyan Department of Biology, United Arab Emirates University, P.O. Box 17551, Al Ain, United Arab Emirates aut NATIONALLICENCE 773 0- Journal of Ichthyology SP MAIK Nauka/Interperiodica 50/11(2010-12-01), 1066-1069 0032-9452 50:11<1066 2010 50 11489 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer