Browsing by Author "Wehrtmann, Ingo S."

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    Egg production of the burrowing shrimp Callichirus seilacheri (Bott 1955) (Decapoda, Callianassidae) in northern Chile
    (2008) Hernaez, Patricio; Palma, Sergio; Wehrtmann, Ingo S.
    The thalassinidean shrimp Callichirus seilacheri is a common species in the intertidal zone of the South American Pacific coast. However, our knowledge of its reproductive ecology is rather limited. The present study was carried out between January and December 2003 at Las Machas, northern Chile. Although ovigerous females were encountered almost throughout the study period, they were particularly abundant between May and September when water temperatures were lowest and sediment coverage of the burrow entrances was highest. Females of C. seilacheri produced numerous (17,450 +/- 3,796 eggs) and small (0.884 +/- 0.080 mm; 0.262 +/- 0.054 mm(3)) eggs when compared to other thalassinidean shrimps for which such information is available. Fecundity was positively correlated with female size; however, correlations were allometric, which might be related to the elasticity of the abdomen. Egg volume increased by 41.2% during embryogenesis, and egg loss during the incubation period was on average 8%. Females inverted on average 14.9% of their dry weight into egg production.
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    Predator control of marine communities increases with temperature across 115 degrees of latitude
    (2022) Ashton, Gail, V; Freestone, Amy L.; Duffy, J. Emmett; Torchin, Mark E.; Sewall, Brent J.; Tracy, Brianna; Albano, Mariano; Altieri, Andrew H.; Altvater, Luciana; Bastida-Zavala, Rolando; Bortolus, Alejandro; Brante, Antonio; Bravo, Viviana; Brown, Norah; Buschmann, Alejandro H.; Buskey, Edward; Calderon Barrera, Rosita; Cheng, Brian; Collin, Rachel; Coutinho, Ricardo; De Gracia, Luis; Dias, Gustavo M.; DiBacco, Claudio; Flores, Augusto A., V; Angelica Haddad, Maria; Hoffman, Zvi; Ibanez Erquiaga, Bruno; Janiak, Dean; Jimenez Campean, Anali; Keith, Inti; Leclerc, Jean-Charles; Pedro Lecompte-Perez, Orlando; Ortigara Longo, Guilherme; Matthews-Cascon, Helena; McKenzie, Cynthia H.; Miller, Jessica; Munizaga, Martin; Naval-Xavier, Lais P. D.; Navarrete, Sergio A.; Otalora, Carlos; Palomino-Alvarez, Lilian A.; Gabriela Palomo, Maria; Patrick, Chris; Pegau, Cormack; Pereda, Sandra, V; Rocha, Rosana M.; Rumbold, Carlos; Sanchez, Carlos; Sanjuan-Munoz, Adolfo; Schloder, Carmen; Schwindt, Evangelina; Seemann, Janina; Shanks, Alan; Simoes, Nuno; Skinner, Luis; Yolimar Suarez-Mozo, Nancy; Thiel, Martin; Valdivia, Nelson; Velez-Zuazo, Ximena; Vieira, Edson A.; Vildoso, Bruno; Wehrtmann, Ingo S.; Whalen, Matt; Wilbur, Lynn; Ruiz, Gregory M.
    Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community composition at such geographic scales remains unknown. Using standardized experiments that spanned 115 degrees of latitude, at 36 nearshore sites along both coasts of the Americas, we found that marine predators have both higher consumption rates and consistently stronger impacts on biomass and species composition of marine invertebrate communities in warmer tropical waters, likely owing to fish predators. Our results provide robust support for a temperature-dependent gradient in interaction strength and have potential implications for how marine ecosystems will respond to ocean warming.