Effects of habitat complexity and group size on perceived predation risk in goldfish (Carassius auratus)

© 2018 Blackwell Verlag GmbH Grouping behavior of social ungulates may depend on both predator occurrence and perceived predation risk associated with habitat structure, reproductive state, and density of conspecifics. Over 3 years, we studied grouping behavior of guanaco (Lama guanicoe) families in Chilean Patagonia during the birthing season and determined their response to variation in predator occurrence and perceived predation risk (habitat structure, calf/adult rate, and density of conspecifics). We considered the effect of two predators, puma (Puma concolor) and culpeo fox (Lycalopex culpaeus). We measured two common (family group size and vigilance) and one novel (family group cohesion) behavioral responses of guanaco. Our results show that guanaco family groups adapted their grouping behavior to both predator occurrence and perceived predation risk. Larger family groups were found in open habitats and areas with high puma occurrence, while guanacos stayed in small family groups in areas with high shrub cover or low visibility. Group cohesion increased in areas with higher occurrence of pumas and culpeo foxes, and also increased in smaller family groups and in areas with low guanaco density. Vigilance (number of vigilant adults) was mainly related to group size and visibility, increasing in areas with low visibility, while residual vigilance (vigilance after removing the group-size effect) did not vary with the explanatory variables examined. Our results suggest that a mix of predator occurrence and perceived predation risk influences guanaco grouping behavior and highlights the importance of evaluating different antipredator responses together and considering all predator species in studies aimed at understanding ungulate behavior.

Download Full-text

Growth Rate and Body Condition in Relation to Group Size in Black Widow Tetras (Gymnocorymbus ternetzi) and Common Goldfish (Carassius auratus)

Journal of Nutrition ◽

10.1093/jn/136.7.2078s ◽

2006 ◽

Vol 136 (7) ◽

pp. 2078S-2080S ◽

Cited By ~ 7

Author(s):

Steven M. Priestley ◽

Abigail E. Stevenson ◽

Lucille G. Alexander

Keyword(s):

Growth Rate ◽

Group Size ◽

Body Condition ◽

Carassius Auratus ◽

Black Widow ◽

Goldfish Carassius Auratus

Download Full-text

Response of juvenile goldfish (Carassius auratus) to chemical alarm cues: Relationship between response intensity, response duration, and the level of predation risk

Chemical Signals in Vertebrates 10 ◽

10.1007/0-387-25160-x_38 ◽

2006 ◽

pp. 334-341 ◽

Cited By ~ 17

Author(s):

Xiaoxia Zhao ◽

Douglas P. Chivers

Keyword(s):

Predation Risk ◽

Carassius Auratus ◽

Response Duration ◽

Alarm Cues ◽

Response Intensity ◽

Goldfish Carassius Auratus ◽

Chemical Alarm Cues ◽

Intensity Response

Download Full-text

Predator occurrence and perceived predation risk determine grouping behavior in guanaco (Lama guanicoe)

10.26686/wgtn.12510083 ◽

2020 ◽

Author(s):

EC Iranzo ◽

Heiko Wittmer ◽

J Traba ◽

P Acebes ◽

C Mata ◽

...

Keyword(s):

Predation Risk ◽

Group Size ◽

Habitat Structure ◽

Group Cohesion ◽

Family Group ◽

Lama Guanicoe ◽

Low Visibility ◽

Grouping Behavior ◽

Perceived Predation Risk ◽

Family Groups

© 2018 Blackwell Verlag GmbH Grouping behavior of social ungulates may depend on both predator occurrence and perceived predation risk associated with habitat structure, reproductive state, and density of conspecifics. Over 3 years, we studied grouping behavior of guanaco (Lama guanicoe) families in Chilean Patagonia during the birthing season and determined their response to variation in predator occurrence and perceived predation risk (habitat structure, calf/adult rate, and density of conspecifics). We considered the effect of two predators, puma (Puma concolor) and culpeo fox (Lycalopex culpaeus). We measured two common (family group size and vigilance) and one novel (family group cohesion) behavioral responses of guanaco. Our results show that guanaco family groups adapted their grouping behavior to both predator occurrence and perceived predation risk. Larger family groups were found in open habitats and areas with high puma occurrence, while guanacos stayed in small family groups in areas with high shrub cover or low visibility. Group cohesion increased in areas with higher occurrence of pumas and culpeo foxes, and also increased in smaller family groups and in areas with low guanaco density. Vigilance (number of vigilant adults) was mainly related to group size and visibility, increasing in areas with low visibility, while residual vigilance (vigilance after removing the group-size effect) did not vary with the explanatory variables examined. Our results suggest that a mix of predator occurrence and perceived predation risk influences guanaco grouping behavior and highlights the importance of evaluating different antipredator responses together and considering all predator species in studies aimed at understanding ungulate behavior.

Download Full-text

SEM of Hepatocytes and Biliary Passages in Goldfish Liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080213 ◽

1977 ◽

Vol 35 ◽

pp. 556-557

Author(s):

Waykin Nopanitaya ◽

Joe W. Grisham ◽

Johnny L. Carson

Keyword(s):

Carassius Auratus ◽

Cell Layer ◽

Three Dimensional ◽

Cell Types ◽

Biliary System ◽

Fish Food ◽

Commercial Fish ◽

Goldfish Carassius Auratus ◽

Commercial Fish Food

An interesting feature of the goldfish liver is the morphology of the hepatic plate, which is always formed by a two-cell layer of hepatocytes. Hepatic plates of the goldfish liver contain an infrequently seen second type of cell, in the centers of plates between two hepatocytes. A TEH study by Yamamoto (1) demonstrated ultrastructural differences between hepatocytes and centrally located cells in hepatic plates; the latter were classified as ductule cells of the biliary system. None of the previous studies clearly showed a three-dimensional organization of the two cell types described. In the present investigation we utilize SEM to elucidate the arrangement of hepatocytes and bile ductular cells in intralobular plates of goldfish liver.Livers from young goldfish (Carassius auratus), about 6-10 cm, fed commercial fish food were used for this study. Hepatic samples were fixed in 4% buffered paraformaldehyde, cut into pieces, fractured, osmicated, CPD, mounted Au-Pd coated, and viewed by SEM at 17-20 kV. Our observations were confined to the ultrastructure of biliary passages within intralobular plates, ductule cells, and hepatocytes.

Download Full-text