Time to developmental stage across temperature and food experiments in the larval purple sea urchin, Strongylocentrotus purpuratus

Website: https://www.bco-dmo.org/dataset/963415
Data Type: experimental
Version: 1
Version Date: 2025-06-06

Project
» Collaborative Research: The effects of marine heatwaves on reproduction, larval transport and recruitment in sea urchin metapopulations (Urchin metapopulations)
ContributorsAffiliationRole
Okamoto, Daniel K.Florida State University (FSU)Principal Investigator
Rogers-Bennett, LauraUniversity of California - Davis: Bodega Marine Laboratory (UC Davis-BML)Co-Principal Investigator
Karelitz, Sam E.Florida State University (FSU)Scientist
Simons, Rachel D.University of California-Santa Barbara (UCSB-ERI)Scientist
Ferraro, RacheleFlorida State University (FSU)Student
Munstermann, Maya J.Florida State University (FSU)Student
Mickle, AudreyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Abstract
Trends in development time and time to metamorphic competency across temperature and food availability treatments were measured in Strongylocentrotus purpuratus larvae. Effects of temperature and food availability were tested using a 6 x 4 factorial experimental design with six temperature treatments (10, 12, 14, 16, 18, 20°C) and four concentrations of Rhodomonas sp. microalgae (500, 2500, 5000, 10,000 cells mL-1) for a total of 24 treatment combinations. Developmental stage was determined in>50% individuals were of a certainstage and metamorphic competency was determined when >50% of larvae exhibited tube feet and adhered to the bottle. Time to metamorphic competency decreased exponentially with temperature with larvae at 10°C reaching competency in 61 days, larvae at 12ºC in 33 days, larvae at 14ºC in 29 days, larvae at 16ºC in 25 days, larvae at 18ºC in 22 days, and larvae at 20ºC in 21 days. This dataset includes the treatment combinations and days to metamorphic competency for each treatment combination.


Coverage

Location: Mohawk Reef depth ranges from 4.5m to 6.0 m, Santa Barbara, California
Spatial Extent: N:34.395849 E:-119.718326 S:34.3940708 W:-119.72957
Temporal Extent: 2022-08-29 - 2022-10-29

Methods & Sampling

Trends in development time and time to metamorphic competency across temperature and food availability treatments were measured in Strongylocentrotus purpuratus larvae. Effects of temperature and food availability were tested using a 6 x 4 factorial experimental design with six temperature treatments (10, 12, 14, 16, 18, 20°C) and four concentrations of Rhodomonas sp. microalgae (500, 2500, 5000, 10,000 cells mL-1) for a total of 24 treatment combinations.

Forty S. purpuratus were collected from kelp forests between 2.2 – 8.8 meters from Carpinteria Reef in the Santa Barbara Channel, California in June 2022. Before spawning, individuals were held at 13°C for 4 weeks at UC Davis Bodega Marine Laboratory and were fed 20 grams of Urchinomics Inc. kelp-based pelleted food every other day. 

A homogeneous pool of fertilized embryos were assigned to temperature treatments. Spawning was induced by injecting of 1–2 mL of 0.5 M KCl. Female urchins were placed upside down over 250 mL beakers filled with filtered to 0.1 µm seawater (FSW) at ambient temperature. Eggs were allowed to collect at the bottom of beakers. Sperm was collected dry from the aboral surface and placed on ice in 2.0 mL microcentrifuge tubes until use. Gamete quality was visually inspected with eggs assessed for shape, color, and uniform size and sperm for motility. Eggs from four females were pooled and rinsed before being fertilized by sperm from four males. Approximately equal proportions of gametes from each individual within each sex were represented.  Successful fertilization was determined by 95% of eggs having a fertilization envelope with no polyspermy. Fertilized eggs were rinsed three times with FSW to remove excess sperm to prevent polyspermy. Approximately 2800 embryos (concentration of ~5.5 embryos mL-1) were placed in each 500 mL glass bottles filled with FSW and placed on roller tables to suspend larvae (Karelitz et al. 2020).

Roller agitation tables were constructed to provide water movement for larval sea urchin cultures. Rollers on free moving axles kept larval culture bottles rotating to prevent larvae from settling to the bottom.  Bottles were partially submerged in water baths heated or chilled using Heater/Chillers (TECO US Inc. TK-500) to maintain target temperatures. Embryos were initially stocked in bottles with ambient temperature (16°C) FSW to minimize temperature shock but immediately placed into water baths to allow embryos to acclimate to target temperatures. Each of the 24 temperature x food treatments had four replicate bottles for a total of 96 bottles. Larvae were fed daily starting at 4 days post-fertilization (when larvae were observed to be competent to feed) and water changes and feeding were conducted every 2 days.

Food treatments represented algal concentrations from starvation to ad libitum conditions. Larval sampling was conducted every two days to estimate changes in larval density, morphometry, and competency, in conjunction with water changes and feedings. Developmental stage was determined in >50% individuals were of a certainstage and metamorphic competency was determined when >50% of larvae exhibited tube feet and adhered to the bottle. 


BCO-DMO Processing Description

- Imported "dpf_stage_temp_food.csv" into the BCO-DMO system
- Exported file as "963415_v1_urchins_development.csv"


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Data Files

File
963415_v1_urchins_development.csv
(Comma Separated Values (.csv), 494 bytes)
MD5:a31e2a4674fdfef32adb4cccfc299180
Primary data file for dataset ID 963415, version 1

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Related Publications

Karelitz, S., Lamare, M., Patel, F., Gemmell, N., & Uthicke, S. (2020). Parental acclimation to future ocean conditions increases development rates but decreases survival in sea urchin larvae. Marine Biology, 167(1). https://doi.org/10.1007/s00227-019-3610-5
Methods

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Parameters

ParameterDescriptionUnits
temp

Experimental temperature treatment in celcius

degrees Celsius
food

Experimental food concentration of Rhodomonas sp. micro algae administered to each replicate bottle in cells per mL

cells per mL
days_settled

Numbers of days post fertilization until the majority of larval individuals were ready to settle and at metamorphic competency

days
days_prism

Numbers of days post fertilization the majority of larval individuals were in the prism stage

days
days_fourarm

Numbers of days post fertilization the majority of larval individuals were in the four-arm larval stage

days
days_sixarm

Numbers of days post fertilization the majority of larval individuals were in the six-arm larval stage

days
days_eightarm

Numbers of days post fertilization the majority of larval individuals were in the eight-arm larval stage

days


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Instruments

Dataset-specific Instrument Name
Heater/Chillers (TECO US Inc. TK-500)
Generic Instrument Name
Aquarium chiller
Dataset-specific Description
Bottles were partially submerged in water baths heated or chilled using Heater/Chillers (TECO US Inc. TK-500) to maintain target temperatures. 
Generic Instrument Description
Immersible or in-line liquid cooling device, usually with temperature control.

Dataset-specific Instrument Name
Water baths heated or chilled to maintain target temperature
Generic Instrument Name
circulating water bath
Dataset-specific Description
Roller agitation tables were constructed to provide water movement for larval sea urchin cultures. Rollers on free moving axles kept larval culture bottles rotating to prevent larvae from settling to the bottom. Bottles were partially submerged in water baths heated or chilled using Heater/Chillers (TECO US Inc. TK-500) to maintain target temperatures.
Generic Instrument Description
A device designed to regulate the temperature of a vessel by bathing it in water held at the desired temperature. [Definition Source: NCI] 

Dataset-specific Instrument Name
Nikon dissection scope
Generic Instrument Name
Microscope - Optical
Dataset-specific Description
Developmental stage was determined in>50% individuals were of a certainstage and metamorphic competency was determined when >50% of larvae exhibited tube feet and adhered to the bottle. 
Generic Instrument Description
Instruments that generate enlarged images of samples using the phenomena of reflection and absorption of visible light. Includes conventional and inverted instruments. Also called a "light microscope".


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Project Information

Collaborative Research: The effects of marine heatwaves on reproduction, larval transport and recruitment in sea urchin metapopulations (Urchin metapopulations)

Coverage: Coastal California Waters from San Diego through Mendocino Counties


NSF Award Abstract:
Rapid and extreme warming events such as El Niño and marine heatwaves have had ecological and economic impacts on nearshore marine ecosystems. These impacts include reductions in biomass and collapses in commercial fisheries. For many species, population booms and busts are controlled by shifts in reproduction and juvenile dispersal related to warmer temperatures and ocean circulation. However, how population fluctuations are shaped by interacting processes that control adult reproduction and larval survival remains unclear. Marine heatwaves often accompany major disruptions in ocean circulation, which can affect survival and the distribution of species that produce free-floating, planktonic larvae. As a result, species can be impacted directly by temperature effects on organismal reproduction and survival, and indirectly by shifts in ocean circulation that affect larval success. This project is examining how the joint effects of temperature and ocean circulation are controlling populations of purple sea urchins (Strongylocentrotus purpuratus). To address project objectives, the team is developing oceanographic models to predict dispersal of planktonic larvae in combination with controlled experiments on adult reproductive success. This project is advancing the understanding of how ecologically important species respond to ocean temperature and circulation, which are forecast to shift under future climate change scenarios. Broader impacts of the project include training of students and post-docs in STEM and educational outreach. Curriculum development and implementation is occurring in collaboration with existing K-12 outreach programs that focus on underserved communities and under-represented groups. The goal is to empower the next generation of scientists to use integrative approaches to predict ecological consequences of climate change.

Purple sea urchins are an ideal species for studying the coupled impacts of warming and ocean circulation on recruitment and survival given a wealth of ecological and organismal data. The species has a mapped genome, can be transported large distances as larvae by ocean currents, and larval abundances in California exhibit orders of magnitude variation with heatwaves and El Niño fluctuations. To quantify the processes that shape spatial and temporal variability in larval supply, researchers are applying a novel combination of biophysical modeling, experiments and statistical modeling of long-term, high-resolution data on larval settlement across the Southern California Bight (SCB). Research module 1 is quantifying spatial and temporal patterns of larval transport using a 3D-biophysical model of the SCB. The model is testing how interactions among historical changes in ocean circulation and temperature, larval life history, and larval behavioral traits affect variation in larval supply in space and time. Research module 2 is focused on how temperature could affect spatial and temporal variation in egg production. Experiments are characterizing reproductive thermal performance curves and quantifying how these vary among populations and organismal history. A novel assay is assessing epigenetic regulation of gene expression associated with performance curves. Finally, Module 3 will integrate mechanistic models from Modules 1 and 2 to statistically assess their ability to explain spatial and temporal trends in a nearly three-decade dataset of larval settlement from six sites in the SCB. This is one of the first studies that integrates models of larval transport, reproductive performance and settlement data to empirically test how physical and biological processes affect local recruitment patterns in complex marine meta-populations.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)
NSF Division of Ocean Sciences (NSF OCE)

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