Aquaculture: Tiger-Tail Seahorse

The Tiger tail Seahorse, Hippocampus comes, is one of the most visually striking creatures in the ocean. Consequently, they are a prime target for the aquarium trade. Unfortunately, these animals are also collected and processed into pills to be sold in China to address a variety of maladies. 20 million seahorses may be caught each year to support the health supplement market in China. In addition to overfishing, habitat destruction also threatens populations of tiger tail seahorses. Import and export of tiger tail seahorses has been regulated since 2004 by the Convention on International Trade in Endangered Species.

Tiger tail seahorses grow to just over 6 inches long and make their homes on corals or sponges in the western central Pacific Ocean. They are usually yellow or black in color, with alternating stripes running down the length of their body. This pattern of stripes makes them difficult for predators to see clearly.

The above flowchart shows the process of culturing Tiger Tail Seahorses, from: http://www.fao.org/fishery/culturedspecies/Hippocampus_comes/en

Currently, tiger tail seahorses are grown in Vietnam to supply both the aquarium trade and health supplement market in China. Aquaculture of tiger tail seahorses begins with the collection of broodstock from wild populations, which are kept in cages in calm waters. During spawning, females transfer their eggs to male seahorses’ pouches. Baby seahorses, called fry, are born after 10-20 days. Seahorse fry are collected and moved to small indoor tanks where environmental conditions can be extensively monitored and controlled. In these tanks, fry are fed copepepods and brine shrimp for around 40 days. Next, fully-grown tiger tail seahorses are transferred to larger indoor tanks or back to cages in bays. They are allowed to grow to acceptable for sizes for sale, usually about 3 inches, which takes approximately 3 months.

Tiger Tail Seahorse fry being grown in a tank. From: http://www.fao.org/fishery/culturedspecies/Hippocampus_comes/en

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links please go to ocean.tamu.edu and click On the Ocean.

Script Author: Arthus Copeland

Contributing Professor: Dr. Lisa Campbell

Editor: James M. Fiorendino

Featured Image: https://www.earth.com/animals/tiger-tail-seahorse-hippocampus-comes/

Aquaculture: Atlantic Salmon

Salmon runs are a major event in Alaska and the Pacific North West, when these anadromous fish return to the rivers where their lives began to spawn. Once, salmon runs were common on the East coast of North America, as well. The Atlantic salmon, Salmo salar, could once be found in almost any river north of the Hudson River in New York; aggressive commercial fishing severely depleted populations of Atlantic Salmon before their closure in 1948. Today, only a handful of wild United States Atlantic Salmon can be found in rivers in Maine. Canadian and European populations of Atlantic Salmon are declining, as well, and all Atlantic salmon sold commercially comes from aquaculture. 

from: http://www.fao.org/fishery/culturedspecies/Salmo_salar/en

Salmon eggs are obtained from broodstock, a population of adult fish reserved for reproduction. Once fertilized, atlantic salmon eggs are incubated at a nursery until they hatch. Newly hatched salmon, called fry, are closely monitored and given vaccinations to preserve their health as they grow into parr. At about 18 months, parr undergo considerably physiological changes that allow them to survive in salt water. At this stage they are about 5 inches long and are called smolts. Smolts are moved to floating nets in mid-April or May. Open-water pens are a practical way of maintaining Atlantic salmon stocks in salty water they need to survive, and the exchange of water in the pens with the surrounding environment removes waste and supplies oxygen-rich water for the salmon.

Though there has been considerable success in farming Atlantic Salmon, many challenges remain. In particular, salmon aquaculture may threaten wild populations and the surrounding environment through excessive nutrient loading and pollution or the transmission of diseases should any stocks escape.

Atlantic salmon production, from: http://www.fao.org/fishery/culturedspecies/Salmo_salar/en

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean. 

Contributing Professor: Dr. Lisa Campbell

Script Author: Judson Riley

Editor: James M. Fiorendino

Featured Image from:

Aquaculture: Nori

Nori is the Japanese name for seaweed and a common component of sushi. Nori is made using red algae belong to the genus Porphyra; it is shredded and dried into sheets which are used to wrap sushi rolls.

Dried sheets of Nori, as would commonly be used to wrap sushi rolls. From: https://upload.wikimedia.org/wikipedia/commons/b/be/Nori.jpg

Porphyra grows on rocky coasts around the world. They are capable of surviving periods of total dryness, and are often found at the upper edges of intertidal zones. Blades can range from less than an inch to several feet in length.

Porphyra have a complex life cycle; The thallus, or body, of Porphyra you can see in a tide pool, produce male and female cells which are released into the surrounding water. Male cells fertilize the female cells, forming spores, which are themselves released into the water before settling and boring into shells, where they grow into a filamentous mass called a conchocelis. The conchocelis, under certain conditions, release spores that will grow into a new blade.

Life cycle of Porphyra yezoensis, from Takahashi and Mikami (2017). https://www.frontiersin.org/files/Articles/238074/fpls-08-00062-HTML-r2/image_m/fpls-08-00062-g001.jpg

Aquaculture of nori is most common in China, Japan, and Korea, but is growing in North America. A two-stage process is required to grow nor because of its complex life cycle. During the first stage, usually between May and October, the filamentous conchocelis stage nori are placed in a reservoir with seawater and nutrients to induce spore production. Following this phase, temperature and light intensity are manipulated to induce the release of spores, which are collected on nets; when spore release reaches are certain threshold, light intensity is increased to encourage growth of the thallus stage of Porphyra. Once settled on nets, Porphyra are grown in the sea or intertidal waters, and harvested after 40 or 50 days.  

Porphyra ready for harvest, from: http://english.jschina.com.cn/PhotoGallery/201203/t966519.shtml

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click “On the Ocean.

Contributing Professor: Dr. Lisa Campbell

Script Author: Martha Navarro

Editor: James M. Fiorendino

Featured image from: https://upload.wikimedia.org/wikipedia/commons/3/36/Porphyra_umbilicalis%2C_Porphyra_purpurea_Helgoland.JPG

Aquaculture: Red Drum

The Red Drum, Sciaenops ocellatus, is a popular fish for food and recreational fishing in the United States along the Atlantic and Gulf coasts. Red Drum are euryhaline, which means they can tolerate a range of salinities in the waters they inhabit. Red Drum are usually brown or reddish, with white bellies, a blunt snout, and wide mouths. They have two fins along their arched back; the forward fin is composed of ten spines.


Aquaculture of Red Drum began in the 1970s, when commercial and recreational fishing depleted natural populations. Artificial stocks were intended to support natural stocks and allow them to recover. Today, Red Drum are primarily grown in Texas and Florida, using highly intensive methods of production. Red Drum aquaculture facilities must either buy eggs from hatcheries, or rely on their own broodstock, which are an independently maintained mature population for breeding. Luckily, Red Drum do well in captivity and reliably reproduce.
Red Drum must be tricked into spawning by creating artificial seasonal cycles. The tanks broodstock are kept in are cooled to 60 degrees F, and a simulated day-night cycle is created to mimic winter daylight hours. Temperatures and daylight hours are gradually altered to simulate the transition of winter to spring, which induces spawning. Eggs are then collected and transferred to hatchery tanks. As the Red Drum grow, they are periodically transferred to larger tanks and, ultimately, ponds until they are large enough for harvest, usually around 2 pounds. Red Drum are usually sorted by size, to discourage cannibalism and maximize production.

The diagram above describes the process of growing Red Drum during aquaculture, from the Food and Agriculture Organization of the United Nations, http://www.fao.org/fishery/culturedspecies/Sciaenops_ocellatus/en


This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click “On the Ocean.

Editor: James M. Fiorendino

Script Author: Jacob Lambert

Contributing Professor: Dr. Lisa Campbell

Featured image from: http://gcrl.usm.edu/public/fish/red.drum.php