Monday, October 6, 2014

Larval Rearing of the Purple Masked Angelfish (Paracentropyge venusta) Using Only Cultured Food

Figure 1. 25 day post hatch Purple Masked Angelfish larva.
Over the past year while working on our Rising Tide project, the larval rearing work has focused on the Purple Masked Angelfish Paracentropyge venusta. We had success on our fifth rearing trial in getting the larvae to the juvenile stage. That larval trial started in November of 2013 and the success was most likely brought about through the use of wild plankton collected from Kaneohe Bay. Plankton was collected almost daily in an effort to provide the larval fish with the necessary nutrients to get them through the larval phases, past metamorphosis and into the juvenile stage. Although we were happy with this accomplishment it meant that larval rearing of this species might be dependent and only possible in areas near a source of wild plankton. In an effort to make larval rearing successful in any location our next step was to try and rear the P. venusta using only cultured food items.

Figure 2. 44 day post hatch Purple Masked Angelfish larva.
On our third try while using only cultured foods for the P. venusta larvae we had success again to the juvenile stage. This larval run, “Trial 8” started on June 28, 2014 and the juveniles are currently just over three months old wearing their beautiful yellow and blue colors and are fully transitioned onto frozen and flake foods.  The food items used for this trial were the calanoid copepod, Parvocalanus crassirostris, the rotifer, Brachionus plicatilis, and the brine shrimp Artemia salina. We were pleasantly surprised that this larval run was on a faster track as compared with our successful wild plankton fed larval run which was quite long. The temperature of this run averaged 26C whereas out trial 5 temperature averaged 25C and this of course could be the reason for faster larval development. We also had a better percent survival with Trial 8 showing 20% survival at day 40 compared to trial 5 at 8.5% survival at day 40. The larvae in Trial 8 were able to capture larger prey starting at day 12 while the larvae in Trial 5 were closer to day 30 when they were able to catch larger prey. The transition to non living foods for the fish in trial 5 took place at 137 days old, which is more than six weeks longer than the fish in trial 8! So not only is it possible to rear these angelfish on only cultured foods, they actually did better on it in terms of survival and development through the larval phase.

October brings to an end the year I had working as part of the Rising Tide team. As I conclude this year I hope that those of you out there who are interested in the captive rearing of marine fish will continue on with what we have learned here. I feel that the small scale breeder can make a significant difference in the numbers and species of fish raised in captivity and I encourage you all to continue on with your efforts. I truly appreciate having been involved in a Rising Tide project and I’m extremely grateful to Rising Tide Conservation for giving me the opportunity to focus solely on marine ornamentals this past year.



Monday, September 22, 2014

Matthew DiMaggio joins TAL; PhD Posting

Figure. Dr. Matthew DiMaggio joins TAL and Rising Tide.
Matt DiMaggio joined the University of Florida’s Tropical Aquaculture Laboratory in 2014 as an assistant professor.  His research program focuses on the culture of ornamental fish species in Florida and he works closely with the local industry to identify opportunities for optimization and innovation. Dr. DiMaggio has a broad foundation in the field of aquaculture, having conducted research with both marine and freshwater species produced for food, bait, and ornamental purposes. His previous investigations have focused on a myriad of applied culture aspects including live feed production, larval rearing, and induced spawning. Additionally, elucidation of basic physiological responses within a species can provide an opportunity for intervention or manipulation to achieve desired outcomes in a production setting. Consequently, reproductive endocrinology, stress physiology, and osmoregulation, are areas of particular interest to him due to their importance for the successful propagation of fishes in captivity. Matt is very excited to contribute to the ongoing research efforts of Rising Tide and he believes that the open dialogue fostered through this collaboration will help to accelerate the commercialization of many of these challenging marine species.

Dr. DiMaggio is currently accepting applications for a four year PhD research assistantship investigating production methods for ornamental fish species in Florida. Please follow the link below for further information .

The Rising Tide team at the Tropical Aquaculture Laboratory

Tuesday, September 9, 2014

Rising Tide at MACNA 2014

Figure. Samantha Groene in the Rising Tide booth at MACNA 2014.
Hello Everyone!

My name is Samantha Groene, and I am a biological technician at UF-TAL. I’ve been with the lab for almost two years, but this is my first official introduction on the Rising Tide Conservation blog. This past week, some of you might have seen me in Denver. The annual Marine Aquarium Conference of North America (MACNA) took place in Denver, Colorado this year, and I had the privilege of representing Rising Tide at the conference!

This year's MACNA was quite the experience! I met so many wonderful people, made a lot of new contacts, and had an overall great time. MACNA is a great opportunity for Rising Tide to be able to communicate the importance of aquaculture to hobbyists and help foster a better future for the critters that we all love. It was very rewarding raising awareness for Rising Tide -- meeting hobbyists, vendors, and exhibitors and sharing with them a cause that is so important for our hobby and our reefs.

I brought with me to MACNA some of our F1 semicircle angelfish to put on display at the Rising Tide booth and at the Boyd Enterprises booth. These fish were some of the stars of the show, and later were raffled off (along with a complete aquarium set-up and other livestock/drygood goodies) to two lucky winners. Of course, there were a lot of other highlights at MACNA. I am sure many of you have heard, but the announcement at MACNA of Karen Brittain’s success rearing the Masked Angelfish (Genicanthus personatus) pretty much stole the spotlight at this year’s conference. However, I will leave it to Karen to apprise you all of the juicy details of that larviculture endeavor.

I would like to thank the wonderful sponsors and people who helped make Rising Tide's presence at MACNA possible and made the event such a success. Specifically, I would like to thank the SeaWorld & Busch Gardens Conservation Fund, Boyd Enterprises, the Denver MACNA Committee, and everyone that donated items for the aquariums that we raffled off at MACNA (thank you JBJ, Martin Moe, and A & M Aquaculture!). I really appreciate all of your support and generosity! All of you helped to make MACNA awesome, and I am very grateful for the opportunity that I was given to serve as the Rising Tide Ambassador at this year’s conference.

I am very happy to have a job where I feel like I make a difference in this world for the better, and it was a great pleasure being able to share my work with MACNA.

Until next time!


Wednesday, August 20, 2014

Rising Tide Intern Joe Frith

Hello Everybody!  My name is Joe Frith and I have been interning here at the Tropical Aquaculture Laboratory in Ruskin, FL for the past 2 months. I would first like to say “thank you” to Dr. Judy St. Leger, Eric, Kevin, Roy, Craig, Jon and the rest of the staff here at the Lab for giving me this opportunity and making this a meaningful experience. I’m currently an undergraduate at the University of Missouri-Columbia completing my degree in Fisheries and Wildlife with a minor in Biology. As a child growing up in the woods of Missouri I was always very intrigued by the natural world and usually had several different aquariums spread throughout my house at any one time. My interest in the aquatic world slowly evolved from freshwater aquariums to saltwater aquariums to eventually trying my hand at breeding the Bluestripe pipefish (Doryrhamphus excisus), which I had help with from Matt Pederson and the other members at It was back in February of this year, after reading posts on the Rising Tide blog that I decided to contact Dr. St. Leger about possible internships they may be awarding for the summer. I received an email shortly after and we soon started laying the groundwork for me to become an intern at TAL. What was once a dream was now a reality.

Over the course of this summer I have helped the Rising Tide team with a number of different projects ranging from Pacific blue tang and emperor angelfish spawning to water quality refinement in an attempt to increase spawning and overall health of all brood fish. Specifically I constructed an algae scrubbing device, complete with mangroves, which has made a significant impact on lower the nitrate levels in the fish growout system (the details of which will be discussed in a future blog). In addition I have learned a lot about the whole marine fish larval rearing process including egg collection, egg counting, stocking and density, and important first food items such as copepod nauplii and rotifers. And if I wasn’t working on any one of these projects I was traveling alongside Dr. Roy Yanong to one of the many aquaculture farms here in the Ruskin area.

This experience has opened my eyes even further to the wonderful world of aquaculture and I can’t think of any other way I would’ve rather spent my summer. With all of the knowledge and insight I have gained in the past couple of months I hope to continue on in this field and hopefully make some great discoveries.

Another big thanks to the Rising Tide team for such an awesome experience!

Best Regards,

Joe Frith


Monday, July 28, 2014

Golden Trevally

Figure 1. Golden trevally eggs near hatching.
We were excited to receive 20 mature golden trevally from SeaWorld Orlando nearly a year ago. We distributed 10 fish each into two large recirculating systems. We expected to have fish spawning within a couple weeks, but after nearly a month of no spawning activity we concluded the fish were likely regressing due to transport and handling stresses. We decided to forgo any more spawning procedures until earlier this year, once the fish had become better acclimated to their new setting and temperatures were in the range reported for spawning. This paid off in mid-April after daily ambient temperatures were averaging close to 26°C and conditioned females were verified through cannulation. We administered spawning hormones to all 10 fish within that tank and obtained three spawns occurring 48, 72, and 96 hours after hormone administration. The first spawn contained mostly sinking (unfertilized) eggs but the next two spawns each contained a majority of neutrally buoyant eggs (~0.7 mm diameter). Hatching occurred quickly (~18 hours) with roughly 60,000 larvae hatched from the second spawn and 36,000 from the third spawn.

Figure 2. 14 days post hatch golden trevally larva.
Larvae were stocked into multiple 104 L tanks supplied with flow-through seawater to exchange a minimum of two tank volumes of water daily. Larvae from the second spawn were stocked into three tanks at nearly 15,000 larvae/tank and larvae from the third spawn were stocked into two tanks at a density near 18,000 larvae/tank. Development was rapid and larvae had fully functioning mouthparts within two days post hatch (dph). We fed the larvae enriched (Ori-Green) rotifers at 10-15 rotifers/mL daily until 25 dph.  We also fed the larvae copepod nauplii (Parvocalanus sp.) at 2 naups/mL daily until 10 dph. By 11 dph, most larvae were able to feed on Artemia nauplii and were fed them at 4 Artemia/mL. We used green water techniques by inoculating larval tanks with live T-ISO (~100,000 cells/mL) up to 25 dph. We began weaning the fish onto a dry diet (Otohime B1-B2) around 15 dph, and after 30 dph fish were feeding solely on the dry diet. During these trials, swim bladder inflation began at 5 dph, fin ray branching at 9 dph, and flexion at 14 dph. The typical black bar pattern and gold coloration could be seen developing as early as 20 dph with all larvae having reached metamorphosis by 30 dph. We observed a mean survival to metamorphosis around 6.5% and obtained over 3,200 juveniles. We restocked them into recirculating systems and raised them for a couple more weeks before they were shipped off to SeaWorld at 45-46 dph around 3.8 cm fork length and 0.94 g.
Figure 3. 30 days post hatch golden trevally larva beginning
to display black bars.

On multiple occasions we’ve administered hormones to both tanks of brood fish and have observed spawning to occur 48-96 hours after administration every time. The quality of spawns has been somewhat variable. We believe golden trevally commercial scale culture to be highly feasible and could be further improved by defining larval culture requirements and optimizing brood fish spawning procedures. We look forward to receiving new species to work with and hope to overcome any difficulties that might inhibit their aquaculture potential.

Figure 4. 45 days post hatch golden trevally juveniles.
Aquaculture lab at the University of Florida Indian River Research and Education Center in Fort Pierce, FL (Dr. Cortney Ohs, Dr. Jason Broach, Bryan Danson, Dan Elefante, Scott Grabe, Andrew Palau, and Audrey Beany)

Tuesday, July 22, 2014

Rising Tide expands in Florida

The University of Florida’s Indian River Research and Education Center (IRREC) is the latest research facility to join our growing Rising Tide family.  Dr. Cortney Ohs heads up the Aquaculture Research and Demonstration Facility at IRREC and has made leaps and bounds in the realms of marine baitfish, marine live feeds, and brood nutrition research since joining UF in 2005.  His expertise and expansive facility will greatly enhance the progress desired in the world of marine ornamental fish research. 

Figure.  Golden Trevally grown at IRREC.  Eggs were spawned from
broodstock received from SeaWorld Orlando. 
About a year ago, Cortney began his involvement with a shipment of golden trevally broodstock from SeaWorld Orlando.  He has since raised 1000’s of them to the juvenile phase, the details of which will be presented in a future blog post.  More recently he has acquired funding that will bring green chromis broodstock to his facility so he and his team can begin to address the production protocols required to make this heavily imported species an aquaculture reality.  TAL and IRREC will be working together closely on this species as well as the Pacific blue tang.  Cortney is currently working on getting Pacific blue tang broodstock so we can double our research efforts and continue to understand the parameters necessary to make this fish a captive bred species as well.  In addition, he will also be receiving shipments of eggs from public aquariums, targeting specific species of interest.

I am personally excited to have Cortney added to the expanding list of Rising Tide research facilities as I obtained my master’s degree studying in his lab.  Try not to hold that against him though, as he did the best he could J.  It is truly an exciting time for Rising Tide as it continues to grow and the separate teams continue to work together, propelling the research forward.

Eric Cassiano and the Rising Tide team at TAL    

Monday, June 30, 2014

Emma Forbes update: Understanding Bacteria at OI

Figure 1. Culture of bacteria (Pseudomonas sp.??) on marine
agar isolated from larval rearing tanks at OI.
Aloha everyone!

It’s been a while since my last post, but it’s been a busy few months. Though it's the kind of busy you don't realize until you sit down and catch your breath. It’s been a lot of fun spending my days in the lab working with everyone learning new things.

Figure 2. Sample of Parvocalanus nauplii on TCBS agar that
was fed to yellow tang larvae.
Since we are still observing relatively high mortality just past first feeding, my work at the Oceanic Institute is focused on bacterial population analysis and application of probiotics to our yellow tang larval rearing tanks. The first month of summer was spent looking at the growth of our live feeds with the addition of probiotics, which appear to have no effect on their survival or growth. This is great news for us! We’ve started to culture our copepods in probiotic-enriched water for larval rearing trials starting July!

Figure 3. Gel electrophoresis of 12 different
bacteria isolated from systems at OI.
My thesis is looking at the identification of bacteria in our culture environments and live feeds and their impact on larval survival. Much of June has been spent practicing different plating techniques, isolating different colonies and running PCR. It’s been very exciting, as there are over 15 different colonies that I’ve isolated and am now working to identify them. This will hopefully give us insight into the bacterial communities in our rearing tanks and any possible pathogenic bacteria that may be affecting yellow tang survival.

In one of my first trials a bright pink bacteria was growing in the tanks. I was able to sample it and isolate it on marine agar. Hopefully in a week or so I will be able to sequence it and determine exactly what species is growing in our hatchery! The unanimous hypothesis is that it’s a Pseudomonas sp., so everyone is very excited to see if they are right! Bets have been placed.

I’m excited to continue larval rearing trials with the probiotics in July to see if they help us increase survival past first feeding!  Fingers crossed!