Seminario del Depto. de Plancton y Ecol. Marina, Miércoles 27 de Abril

SEMINARIO DEL DEPARTAMENTO DE PLANCTON

Y ECOLOGÍA MARINA

MIÉRCOLES 27 DE ABRIL

11:00 AM-12:00 PM

Aula Magna

Genetic evidence of distinct new Collinia species, parasitoids of krill from the Bering Sea to the Baja California peninsula region

Jaime Gómez-Gutiérrez1, Michaela C. Strüder-Kypke2, Denis H. Lynn2, C. Tracy Shaw3, Alejandro López-Cortés4, Mario J. Aguilar-Méndez5 and Carlos J. Robinson6

1Departamento de Plancton y Ecología Marina, Centro Interdisciplinario de Ciencias Marinas (CICIMAR), La Paz, B.C.S., 23096, Mexico. E-mail: jagomezg@ipn.mx

2Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada

3Cooperative Institute for Marine Resource Studies, Hatfield Marine Science Center, Newport, OR, 97365, USA

4Laboratorio de Ecología Microbiana Molecular, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz, B.C.S. 23096, Mexico

5Instituto Politécnico Nacional (IPN), Unidad Profesional Interdisciplinaria de Ingeniería (UPIIG), Silao de la Victoria, Guanajuato, 36275, Mexico

6Laboratorio de Ecología de Pesquerías, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, AP 70-305, México, D.F. 04510, Mexico 

To explore the ecological function and host specificity of krill parasitoids, we used molecular methods to identify three Collinia species, ciliates that kill the seven most abundant and trophically relevant krill species in the Northeastern Pacific Ocean (23–55°N), occasionally causing massive epizootic events. Genetic evidence showed host specificity: Collinia beringensis infects Thysanoessa inermis, Thysanoessa raschii, and Thysanoessa longipes in the Bering Sea; Collinia oregonensis infects Euphausia pacifica, Thysanoessa spinifera, and Thysanoessa gregaria along the Oregon and California coasts; and an as-yet undescribed species of Collinia infects the sac-spawning Nyctiphanes simplex along the west coast of Baja California and in the Gulf of California. The new Collinia species revealed two novel features of the Collinia life-cycle: (1) all life stages are associated with opportunistic bacterial assemblages that can end in bacteremia; and (2) the encysted cells or phoronts form dense ciliate-bacterial mucilage filaments, probably mixed with marine snow, that apparently infect krill when they are ingested. This latter conclusion is based on 16S rRNA gene sequences from bacterial assemblages derived from Collinia at each life stage, from bacterial communities from the stomachs of healthy krill, and from the hemocoel of infected krill. Our genetic evidence also suggests that the Collinia-krill parasitoidism has co-evolved as an interaction independent of the host reproductive strategy (i.e., broadcast or sac-spawning). We predict that parasitoid-krill interactions occur in other krill species of the Order Euphausiacea, with yet undefined effects on mortality rates and population dynamics.

About Sylvia Patricia Jiménez Rosenberg

Afiliación: Centro Interdisciplinario de Ciencias Marinas del Instituto Politécnico Nacional (1998-Actual). Grado Académico: Doctorado en Ciencias Marinas (CICIMAR-IPN) Tésis: Asociaciones de larvas de peces por estadio de desarrollo en la costa noroccidental de la Península de Baja California. Área de conocimiento: Taxonomía y Ecología del Ictioplancton. Proyectos: -Larvas de peces como indicadores de la variabilidad ambiental en ecosistemas pelágicos del Pacífico Mexicano (Director). -Investigaciones Mexicanas de la Corriente de California (Programa IMECOCAL) (Participante).
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