O?ahu has the lowest population of ?opihi, endemic intertidal limpets, across the Hawaiian Islands. To help rebuild the population of this Hawaiian delicacy, two graduate students at the University of Hawai?i at ²Ñ¨¡²Ô´Ç²¹ (CTAHR) are attempting to spawn and rear ?opihi to adulthood in their lab on campus.
Angelica Valdez and Mitch Marabella are trying to complete the ?opihi life cycle. To do that, they would need to spawn and fertilize an ?opihi in the lab, grow that ?opihi so that it can reproduce, and transplant the offspring back into the wild.
¡°The dream goal is to get all the way through the life cycle,¡± said Valdez. ¡°We¡¯ve come pretty close. The 30-day ?opihi animal was the first where we¡¯ve had records of shell growth. That is the longest we¡¯ve had, it was really incredible that we got it that far.¡±
Spawn trials
To re-establish the population, Valdez and Marabella are conducting spawn trials in the lab, a process that can take up to 36 hours overnight. They start by introducing a peptide hormone to the ?opihi and place them into a spawning container. During that time they will record measurements and continue to check on the ?opihi every hour.
Peak spawning times are between midnight and 3 a.m. Once the ?opihi spawn, the students begin checking on the animals and the quality of the water and containers. One person counts the eggs while the other is fertilizing. After spawning, there is an 8¨C12 hour lull until researchers do a larval transfer before the grow out phase.
¡°When we do get a spawn, we have to really rush because ?opihi don¡¯t have a protective shell around the egg so it is susceptible to polyspermy (when multiple sperm enter an egg),¡± said Marabella. ¡°So we have to make sure it is properly fertilized, making our work much more active at night.¡±
So far, Valdez and Marabella have conducted 20 spawn trials. They have also partnered with the , which provides their lab with barrels of salt water for the ?opihi. During a spawning trial, students go through up to 50 gallons of water.
Sustainable harvesting
Students are trying to get ?opihi to a viable stage where the reproduced ?opihi can be outplanted into the intertidal area of the seashore to build up the population again, so that people can harvest responsibly and sustainably.
¡°It¡¯s a long process and that¡¯s why it is harder to look toward farming at this point,¡± said Marabella. ¡°We¡¯re more focused on conservation right now because farming would not be possible if this population is decimated.¡±
Former CTAHR students began trying to re-establish the ?opihi population on O?ahu in 2007. Since then, the project has been handed down to the next cohort of students. Valdez began working on the project in 2018 and Marabella joined the project in 2020.
¡°We never want to stop people from harvesting. It is a tradition with family and it is cultural to Hawai?i,¡± said Valdez. ¡°Our goal is to build back up the ?opihi population so that it is sustainable for everyone to harvest.¡±
