Periodic Reporting for period 1 - EnvIronchannel (Making a choice for life – Cellular and molecular basis of coral larvae settlement and metamorphosis.)
Periodo di rendicontazione: 2023-05-01 al 2025-10-31
Corals are sessile animals that form the basis for some of the most diverse marine ecosystems on the planet. Being constrained to one place for the majority of their life, sessile marine invertebrates cannot escape should conditions become unfavorable. To solve this problem, corals have a biphasic lifecycle with a motile larval stage that can disperse and conquer new habitats. How coral larvae disperse and subsequently identify a suitable habitat remains enigmatic in most species. Lophelia Pertusa is a framework-forming cold-water coral with a global distribution and important ecosystem function that can serve as a study object for these questions, due to its accessibility here in the Trondheimsfjorden and its slow larval development.
The ongoing project is pioneering investigations into the mechanistic basis of the dispersal and settlement phase of the coral larvae. We aim to understand how the larvae change over the course of development, to fulfill stage specific needs, such as to disperse away from the parental colony – which is believed to be a largely passive process, and the subsequent phase in which the animal becomes “competent” to recognize specific, suitable habitats and settle to form a new sessile colony- which is believed to be a mainly active process. To achieve these goals, we study the changes in behavior, anatomy and molecular composition of the animals in different developmental stages to identify stage specific sensory modalities and effector systems that enable the animal to successfully master this phase of its lifecycle.
The project is producing fundamental knowledge about coral larval dispersal and habitat selection. Such knowledge is urgently required for us to understand which impact environmental changes have on this central process.
The ongoing project is pioneering investigations into the mechanistic basis of the dispersal and settlement phase of the coral larvae. We aim to understand how the larvae change over the course of development, to fulfill stage specific needs, such as to disperse away from the parental colony – which is believed to be a largely passive process, and the subsequent phase in which the animal becomes “competent” to recognize specific, suitable habitats and settle to form a new sessile colony- which is believed to be a mainly active process. To achieve these goals, we study the changes in behavior, anatomy and molecular composition of the animals in different developmental stages to identify stage specific sensory modalities and effector systems that enable the animal to successfully master this phase of its lifecycle.
The project is producing fundamental knowledge about coral larval dispersal and habitat selection. Such knowledge is urgently required for us to understand which impact environmental changes have on this central process.
A complex prosses like dispersal and settlement in coral larvae, requires many subsystems. To understand how some of these components, e.g. molecular and cellular components shape this complex behavior, we need to obtain knowledge about them. To this end, we established cnidarian electrophysiology and the identification of ion channels from non-model organisms (Davila-Velderrain and van Giesen 2025, bioarxiv). This collaborative effort is a key cornerstone of the future work in Lophelia and will enable us to study coral cellular physiology and identify potential ion channel and receptor candidates that are involved in sensory processes that guide the habitat choice of Lophelia larvae.
Another step towards understanding how larvae perform their “tasks” at specific developmental stages includes the behavioral assay that we have developed to analyze the larval swimming in horizontal and vertical planes. The obtained information can shed light on how the larvae is able to navigate the ocean- partially passive, partially active and which sensory input is guiding these specific patterns. Furthermore, this series of experiments can help us understand the competency window- a critical parameter that determines how far larvae can distribute and how successful they can settle.
Another step towards understanding how larvae perform their “tasks” at specific developmental stages includes the behavioral assay that we have developed to analyze the larval swimming in horizontal and vertical planes. The obtained information can shed light on how the larvae is able to navigate the ocean- partially passive, partially active and which sensory input is guiding these specific patterns. Furthermore, this series of experiments can help us understand the competency window- a critical parameter that determines how far larvae can distribute and how successful they can settle.
Working with corals and specifically with their motile larval stage is challenging due to their often difficult to reach locations, the once-a-year spawning and the short timespan that the larvae need for development. In collaborative efforts in this project, we have established and refined housing and experimental procedures for the cold-water coral Lophelia pertusa. These steps have brought about new knowledge, but they will also largely benefit and impact the community enabling other research in this area that will help us to understand and study more details of this critical organismal process.