Browsing by Author "Carrasco, Sergio A."

Now showing 1 - 8 of 8
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    Behavioral and chromatic dynamics describing mating interactions of the south American octopus Robsonella fontaniana (Cephalopoda: Octopodidae)
    (2023) Cifuentes, Victor; Perez-Matus, Alejandro; Fernandez, Miriam; Ibanez, Christian M.; Carrasco, Sergio A.
    Cephalopods are characterized by a substantial behavioral flexibility during reproductive interactions; however, for octopods rather few studies have provided empirical information on the mechanisms operating during male-male and male-female encounters. Using the small south American octopus Robsonella fontaniana (similar to 270 mm total length, similar to 70 mm mantle length), we evaluated the mating behavior based on octopuses from central Chile. Eighteen male-female and five male-male interactions were characterized in laboratory using ethograms divided into precopulatory and copulatory stages. Although subjects' interactions occurred in both treatments, extended mating periods (81-196 min) were only observed in the male-female trials, and specifically, in those involving larger octopuses (39% of the interactions; > 43 mm mantle length). During the precopulatory stage (4-20 min), different behavioral displays were evidenced in 57% of these male-female interactions, including: contact, exhibition of chromatic displays, swimming, and mounting. Larger pairs had longer copulation times, with a maximum of similar to 200 min in octopuses of 50 mm mantle length. The observed mating in adult male-female pairs and the practically null interaction between juveniles suggest that a maturity-conditional reproductive behavior (similar to 43 mm mantle length; similar to 38 gr), could be one of the mechanisms modulating mating interactions of R. fontaniana in the wild, potentially influencing aspects such as mate guarding behavior, possible sperm removal or sperm loading. (c) 2023 Elsevier B.V. All rights reserved.
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    Embryonic and larval traits of the temperate damselfish Chromis crusma reveal important similarities with other Pomacentridae throughout the family's thermal range
    (2019) Muñoz Cordovez, Rodrigo; De La Maza, Lucas; Pérez Matus, Alejandro A.; Carrasco, Sergio A.
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    Environmental and ecological factors mediate taxonomic composition and body size of polyplacophoran assemblages along the Peruvian Province
    (2019) Ibáñez, Christian M.; Waldisperg, Melany; Torres, Felipe Ignacio; Carrasco, Sergio A.; Sellanes, Javier; Pardo Gandarillas, María Cecilia; Sigwart, Julia D.
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    Exploring the effects of fishing pressure and upwelling intensity over subtidal kelp forest communities in Central Chile
    (2017) Pérez Matus, Alejandro A.; Carrasco, Sergio A.; Gelcich, Stefan; Fernández, Miriam; Wieters Buchanan, Evie Ann
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    Maternal Lipid Provisioning Mirrors Evolution of Reproductive Strategies in Direct-Developing Whelks
    (UNIV CHICAGO PRESS, 2016) Carrasco, Sergio A.; Phillips, Nicole E.; Sewell, Mary A.
    The energetic input that offspring receive from their mothers is a well-studied maternal effect that can influence the evolution of life histories. Using the offspring of three sympatric whelks: Cominella virgata (one embryo per capsule); Cominella maculosa (multiple embryos per capsule); and Haustrum scobina (multiple embryos per capsule and nurse-embryo consumption), we examined how contrasting reproductive strategies mediate inter-and intra-specific differences in hatchling provisioning. Total lipid content (as measured in mu g hatchling(-1) +/- SE) was unrelated to size among the 3 species; the hatchlings of H. scobina were the smallest but had the highest lipid content (33.8 +/- 8.1 mu g hatchling(-1)). In offspring of C. maculosa, lipid content was 6.6 +/- 0.4 mu g hatchling(-1), and in offspring of C. virgata, it was 21.7 +/- 3.2 mu g hatchling(-1). The multi-encapsulated hatchlings of C. maculosa and H. scobina were the only species that contained the energetic lipids, wax ester (WE) and methyl ester (ME). However, the overall composition of energetic lipid between hatchlings of the two Cominella species reflected strong affinities of taxonomy, suggesting a phylogenetic evolution of the non-adelphophagic development strategy. Inter-and intracapsular variability in sibling provisioning was highest in H. scobina, a finding that implies less control of allocation to individual hatchlings in this adelphophagic developer. We suggest that interspecific variability of lipids offers a useful approach to understanding the evolution of maternal provisioning in direct-developing species.
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    Predator tactics and prey densities modulate the strength of trophic interactions in a temperate rocky reef
    (2021) Munoz-Cordovez, Rodrigo H.; Carrasco, Sergio A.; Ojeda, F. Patricio; Perez-Matus, Alejandro
    Evaluating the species-specific effects of multiple predators on shared prey helps to identify the mechanisms regulating predator impacts. Here, we investigate the trophic impact of two predators of the Chilean rocky subtidal, the fish Graus nigra [F] and the octopus Robsonella fontaniana [O] on their shared prey, the porcelain crab, Petrolisthes violaceus. Manipulative laboratory experiments were performed to evaluate mortality and behavior of porcelain crab in different treatments, including prey alone; prey with single predator ([O] or [F]); and prey with combined predators ([F + F], [O + O], and [O + F]). Different prey densities (N = 3, 9, and 12 individuals) were used to explore density-dependent predation mortality for single and combined predators using an orthogonal (crossed) design that allows to tease apart the effects of predator taxonomic identity from prey density. Behavioral responses of interacting species were registered every 4 h for 2 consecutive days, and were used to identify predator foraging strategies and prey refuge use. Mortality values (proportional prey mortality and predator per capita consumption) were compared among treatments. Results indicated differences in mortality among treatments. The cause of increase of prey proportional mortality was due to an increase in prey availability outside the refuge in fish treatments at high initial prey densities, while it was density independent in octopus' treatments. Changes in predator per capita consumption were registered depending on the predator combination and the initial prey density. These patterns may reflect contrasting predator foraging strategies and changes in refuge use by porcelain crabs, suggesting effects on prey mortality and predator impacts.
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    Spatial and short-term variability of larval, post-larval and macrobenthic assemblages associated with subtidal kelp forest ecosystems in Central Chile.
    (2017) Carrasco, Sergio A.; Vandecasteele, Loes; Rivadeneira V., Marcelo M.; Fernández, Miriam; Pérez Matus, Alejandro A.
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    Temperate rocky subtidal reef community reveals human impacts across the entire food web
    (2017) Pérez Matus, Alejandro A.; Ospina Alvarez, Andrés; Camus Contreras, Patricio A.; Carrasco, Sergio A.; Fernández, Miriam; Gelcich, Stefan; Godoy Salinas, Natalio; Ojeda Rossi, Federico Patricio; Pardo, Luis Miguel; Rozbaczylo Narvaez, Nicolás; Subida, Maria Dulce; Thiel, Martin; Wieters Buchanan, Evie Ann; Navarrete C., Sergio