Algal Feeds for Shrimp Larvae
A Discussion from the Shrimp List
Todd Blacher (email@example.com): Has anyone ever used Thalassiosira pseudonana for the production of Penaeus vannamei larvae?
John Scarpa (firstname.lastname@example.org): I heard of some work done many years ago by Mary Schilling Clark at Harbor Branch Oceanographic Institution on using Thalassiosira weissflogii, a larger species than T. pseudonana, for P. vannamei larvae culture. There may be an abstract on this somewhere in the World Aquaculture Society archives.
Todd Blacher (email@example.com): I have also used T. weissflogii as a complementary species to Chaetoceros gracilis and/or C. muelleri. My culturing area, however, is very small and the T. weissflogii do not reach high concentrations. I have been culturing T. pseudonana for about four weeks and am getting amazing results (up to 16 million cells per ml), but have not tried to feed them to larvae because I have not cranked up the hatchery yet. Have any of you used T. pseudonana?
Dallas Weaver (firstname.lastname@example.org): Does anyone have experience feeding Spirulina, live or frozen, to penaeid larvae. If yes, to which stages?
John Scarpa (email@example.com): Just remember that cell density is related to cell size. Although weissflogii does not get to the high densities of other species, it does offer a larger chunk (volume, mass), compared to pseudonana. Do you want a dozen White Castle hamburgers or just one Whopper?
Josh Wilkenfeld (firstname.lastname@example.org): Cell size is important, especially during the early zoea stages, and so is the availability of particles for the larvae to encounter, since the early stages of shrimp larvae in particular are continuous filter feeders. Shrimp larvae are not very efficient at digestion and assimilation; they pretty much have to have a constant flow of feed going through their gut to get sufficient energy.
It’s true that weissflogii is one of the most nutritious species of phytoplankton, but its large cell size and relatively low densities in mass culture present two problems: early larval stages have a bit of a problem eating the larger cells and it takes much more floor space to grow them. Also, the cells would have to be concentrated to ensure that the larvae encounter them. Weissflogii usually works best starting at zoea-2 or zoea-3. It’s not a good idea, however, to use weissflogii as the sole, live algae species, at least until the mysis-2 stage, because of the size and availability issues.
I usually start by feeding at about 75-100,000 cells/ml and then add between 2,500-7,500 cells per ml of weissflogii when the larvae reach late Z-2 or Z-3. In the mysis stages, I’ll usually let the muelleri or gracilis densities drop to about 50K/ml, with 5-7.5K/ml weissflogii.
I’ve never worked with pseudonana and can’t say that I know of anyone who has, but that doesn’t mean that it would not be a great species for larval rearing. I tried to find some data on the lipid analyses of various species of diatoms (including weissflogii and pseudonana), but didn’t come up with anything useful during a quick Internet search. I heard a presentation sometime in the early 1980s that gave an analysis of various species of algae, and it was at that point that I decided to adopt the use of weissflogii into my feeding regime because, as I recall, it was second only to Skeletonema costatum in terms of its fatty acid profile. Weissflogii has always been much easier for me to handle in commercial-scale mass culture systems than S. costatum. I love the idea of the small size of pseudonana and the high cell densities, but lacking any definitive information on its food value or comments from anyone who actually has the experience of using this species with shrimp larvae, I guess what you have to do is give it a try. Todd, it would really be great if you ran some comparative trials with muelleri or gracilis.
Regarding Dallas’s question about the use of live or frozen Spirulina in larval feeding, many shrimp hatchery operators, including me, use commercially available dry Spirulina (INVE has a very good product) on a regular basis as a standard feed supplement beginning with zoea-1. I’ve also used Spirulina as a component of a moist maturation pellet that we produce on site. I’ve never tried culturing or feeding live Spirulina, and I’m afraid I’m not a big fan of frozen algae. I believe that the cell quality and nutritional value is diminished in the process of freezing, and you just end up with very dirty tanks and underfed larvae.
Phil Boeing (email@example.com): I concur with all the other postings on this subject and would like to add the following:
Pseudonana is excellent algae for all stages of penaeid larvae. It is most widely cultured for feeding various species of bivalves because it is more of a coldwater species than the higher temperature tolerant weissflogii and the various Chaetoceros species. In some earlier work, weissflogii was used as a complete Artemia replacement for penaeid larvae at the Oceanic Institute. The Thalassiosiras are very high in cholesterol and HUFAs.
Todd Blacher (firstname.lastname@example.org): Thanks. I appreciate your comments. Once I start culturing larvae, if I come up with anything interesting, I’ll share it with all of you.
Samir Kuri (email@example.com): In Belize, I used Spirulina (frozen), pseudonana and weissflogii from zoea 1-2 onward with no muelleri or gracilis. I also used Daphnia with postlarvae and had very good results.
B. Sakthi Mohan Ganesh (firstname.lastname@example.org): On Mafia Island, off Tanzania, I used frozen Spirulina from Z-1 to Z-3 along with supplements and got good performance.
Dallas Weaver (email@example.com): Thanks for the information. I am consulting for a group that hopes to significantly decrease the production cost of Spirulina. Being a much larger algae (50 to 100 µ long), perhaps it could be fed to later stages as a partial Artemia replacement. Frozen Spirulina should be cheaper that Artemia, or any locally produced live algae. I know this market wouldn’t be big, but it could be a fun market. What is your opinion based upon your experience regarding this possible market?
The Shrimp List
The Shrimp List is a free, email-based, unmoderated, mailing list for shrimp farmers that distributes information posted by one member of the list to all the other members of the list. Anyone can use the lists to ask and answer questions, to keep participants up-to-date on a conference, to coordinate a project or to pass industry news around. You don't have to participate in the discussion. You can just sit back and read the messages that interest you.
The easiest way to get on the Shrimp List is to send an email to “firstname.lastname@example.org”. That’s it. Just put the stuff in quotes where you would normally put someone’s email address and you will begin receiving all the postings to the list. To post a message to the list, send your email to “email@example.com”, and to unsubscribe, send your email to “firstname.lastname@example.org”.
Source: The Shrimp List. Subjects: Unknown, Algae Feeds and Thalassiosira sp. November 1-2, 2007.
He Smelled It Before He Saw It
As you’re reading this, some airline passenger’s checked bag is going astray, just the way Austinite Dorian De Wind’s box of shrimp went astray on his way home from Ecuador. When De Wind arrived in Miami, Florida, on his way to Austin, Texas, a gate agent talked him into checking an insulated box of frozen shrimp. Two days later, when the box finally arrived in Austin, De Wind found it sitting in 100-degree heat. He smelled it before he saw it.
Source: Statesman.com. Travel/One long, strange trip (http://www.statesman.com/life/content/life/stories/other/11/11/1111baggage.html). Helen Anders (email@example.com). November 11, 2007.
The Waterbase Limited
Located in Nellore, Andhra Pradesh, The Waterbase Limited is the largest integrated shrimp company (feed mill, hatchery, farm and ultra-modern processing plant) in India. It grows giant tiger shrimp (Penaeus monodon) white shrimp (P. indicus) and freshwater prawns (Macrobrachium rosenbergii) in 110 hectares of ponds. Its hatchery can produce 200 million postlarvae year. Its automated feed mill produces over 150 metric tons of shrimp feed a day.
Waterbase exports shrimp—raw or cooked, peeled or unpeeled, breaded and battered—to markets in Japan, USA and Europe. It follows HACCP (Hazard Analysis Critical Control Point) guidelines, and it’s among the few Indian companies that have FDA approval for exports to the USA.
Waterbase is the company that developed the concept of “Aqualabs”, centers where shrimp farmers can go for help. The labs test water, soil and shrimp and suggest timely steps to ensure successful harvests.
Waterbase is a part of the 80-year-old Thapar Group, one of India’s largest business houses, which has interests in paper, chemicals, glass, textiles, electronics and engineering.
Source: The Waterbase Website (http://www.thewaterbase.com/aboutus.htm). October 29, 2007.
Will Vannamei Fill the Monodon Void?
India’s production of farmed shrimp has stagnated at about 150,000 metric tons, mostly because of disease problems with the black tiger shrimp (Penaeus monodon), the most popular farmed species in the country. Processing facilities are running at about 30% of capacity because of low survival rates at shrimp farms.
India needs to look at alternatives and the white shrimp (P. vannamei) is the best bet, says Ravi Reddy, president of the Seafood Exporters Association (SEA) in the state of Tamil Nadu.
A.J. Tharakan, national president of SEA and vice-chairman of the government trade promotion body, the Marine Products Export Development Authority (MPEDA), says there is apprehension within the industry that vannamei might not be suitable for Indian conditions and that its introduction might contribute to the end of monodon farming. He calls for selective introduction of vannamei at large farms only, where it could be controlled and monitored. “Around 20% of Indian aqua farms are equipped to culture vannamei,” he says. “The rest could continue with black tiger.”
Since vannamei is an exotic species, it still needs government approval before it could be cultured on a wide scale. Currently, two firms in Nellore, Andhra Pradesh—Sharat Seafood, Pvt., Ltd., and BMR Hatcheries, Ltd.—have been allowed to introduce vannamei on an experimental basis. Prasad Reddy, managing director of Sharat Seafood, says: “Even a yield of three tons per hectare of vannamei could be more profitable than a black tiger farm with the same yield.” Sharat Seafood gets its broodstock from the Oceanic Institute in Honolulu, Hawaii, USA, which has developed specific pathogen free broodstock.
According to Tharakan, only those hatcheries that are run by MPEDA should be given permission to import vannamei because they have the ability to control diseases. He said, “Once the government gives its nod, it should ensured that no private hatcheries are allowed to import broodstock.”
Source: LiveMint.com. Marine industry plans to introduce vannamei shrimp (http://www.livemint.com/2007/11/14235649/Marine-industry-plans-to-intro.html). Ajayan. November 14, 2007.
Where Have All the Tigers Gone?
The international market for black tiger shrimp (Penaeus monodon) is eroding because tigers just can’t compete with the cheaper-to-produce, white shrimp (P. vannamei) that’s grown in many Asian countries.
Exporters in India, Bangladesh and Vietnam, the three leading producers of black tiger shrimp, point out that the total retail market in the USA has been completely captured by white shrimp because of its lower price.
P. Brahmanandam, chairman of Devi Seafood, said the competition from white shrimp is becoming a serious problem and that the black tiger market is now restricted to restaurant chains. The decline in demand for black tiger shrimp is also being felt in other major markets like Japan and the European Union.
Shrimp survivals on monodon farms are around 40%. On international markets, the price of monodon is at least 15% higher than vannamei.
Source: The Economic Times. Tiger shrimp exports shrink on global cues (http://economictimes.indiatimes.com/Markets/Commodities/Tiger_shrimp_exports_shrink_
Will Not Reach Production Goals in 2007
The Indonesian Shrimp Commission forecasts that the country’s production of shrimp will fall short of its target of 410,000 metric tons in 2007. According to Commission chairman Shidiq Moeslim, production only reached 220,000 tons through September 2007. He said shrimp prices have fallen to around $6 per kilogram, not high enough to encourage shrimp farmers to increase production.
Source: Seafood.com (an online, subscription-based, fisheries news service). Indonesia’s shrimp production will be far short of 410,000 ton target this year. Ken Coons (phone 781-861-1441, email firstname.lastname@example.org). Editor and Publisher, John Sackton (phone 781-861-1441, email email@example.com). November 8, 2007.
Shrimp Hatcheries on Luzon
A shrimp farmer asks: Does anyone know of a shrimp hatchery on the main Philippine island of Luzon? I currently have one supplier of Penaeus vannamei, but I need other suppliers.
Source: The Shrimp List (a mailing list for shrimp farmers, “firstname.lastname@example.org”). Subject: [shrimp] White vannamei shrimp hatcheries in Luzon, Philippines. From: email@example.com. November 13, 2007.
Do Shrimp and Lobsters Feel Pain?
Scientists have long argued that crustaceans don’t feel pain, even when cooked live in boiling water. But now a British biologist is challenging this orthodoxy. Professor Robert Elwood dabbed acetic acid, the main ingredient of vinegar, on the antennae of 144 shrimp. The shrimp reacted by rubbing the affected parts of their bodies for up to five minutes. The reaction, he said, was exactly the same as that seen in mammals exposed to painful irritants. “The prolonged, specifically directed rubbing and grooming is consistent with an interpretation of pain experience,” he said.
But not everyone agrees with Elwood. Liverpool University’s Dr. Lynne Sneddon, who has investigated whether eels feel pain, said: “You could argue the shrimp were simply trying to clean their antennas rather than showing a pain response.” And Dr. Richard Chapman, of the University of Utah’s pain response center, said there was a difference between responding to an acidic chemical and actually feeling pain. Most animals have sensors that react to irritants, he said, adding: “Even a single-cell organism can detect a threatening chemical and retreat from it. But this is not sensing pain.”
In August 2006, Seafood Business reported that lobsters have a primitive nervous system, similar to that of a cricket or grasshopper. “Basically, lobsters have no brain,” says Robert Bayer, Ph.D., executive director of the Lobster Institute at the University of Maine. “They don’t have the physiological software to process pain. ...I’m not aware of any bona fide studies that suggest lobsters feel pain.” Bayer points to a February 2005 study conducted by a University of Oslo scientist and funded by the Norwegian government that found lobsters and other decapod crustaceans “have some capacity for learning, but it is unlikely they feel pain.”
Then why do live lobsters twitch and hiss when cooked? The twitching is simply an escape mechanism from a threatening stimulus. According to the Lobster Institute, chilling or icing lobsters before cooking minimizes the duration of twitching. Steaming, slow heating in saltwater and hypnotizing (rubbing a lobster’s head) can increase the duration of twitching. The hissing noise that often emanates from a cooking lobster is simply air escaping from the animal’s body cavity as it expands from the heat.
Sources: 1. Daily Mail. Prawns do feel pain, say scientists (http://www.dailymail.co.uk/pages/live/articles/technology/technology.html?in_article_id=
California—Shrimp News International
Hi, I’ve restored the search feature to this site. Give it a try. I use it all the time to search the back issues of Free News.
Source: Bob Rosenberry, Shrimp News International, November 23, 2007.
South Carolina—Another New Job at Waddell
The Waddell Mariculture Center in Bluffton, South Carolina, has a new position open for a shrimp farm technician, in addition to an earlier listing:
Salary: $34,218 to $42,718.
Closing Date: November 20, 2007.
Qualifications: A bachelor’s degree in biology, chemistry or wildlife management and experience in fish, wildlife or marine resource management or research programs. A master’s degree in biology, chemistry, wildlife management or aquatic sciences may be substituted for the required work experience. The candidate must be a USA citizen or must be legally authorized to work in the USA.
Job Description: Oversight of moderately complex marine shrimp aquaculture research projects under the supervision of a primary investigator. Plan and supervise the work of subordinates to ensure that ponds, raceways and tanks are maintained properly and that appropriate biological, chemical and physical data are collected. Compile experimental data for inclusion in reports and publications. Plan and supervise day-to-day animal husbandry operations like feeding, sampling and harvest operations.
Information: Go to “http://agency.governmentjobs.com/sc/default.cfm” and type “Wildlife Biologist” in the keyword section of the search box. It will take you to the job announcement. Press “Apply” and follow instructions.
Information: Dr. Jesus Venero (phone 843-837-3795, extension 131, email firstname.lastname@example.org). South Carolina Department of Natural Resources.
Source: AquaNic (The Aquaculture Network Information Center, a gateway to the world’s electronic aquaculture resources, http://aquanic.org/index.htm). Jobs Directory (http://www.aquanic.org/Text/job_serv.htm) In cooperation with the WAS Employment Service. Search jobs (http://aquanic.org/jobs/search.asp). Biologist-II (http://aquanic.org/jobs/jobinfo.asp?jobid=2634). Posted November 11, 2007.
Washington, DC—World Wildlife Fund Critical of GlobalGAP and GAA Standards
Developing standards to address the environmental impacts of shrimp farming is a top priority of the United Nations Food and Agriculture Organization (FAO), the World Bank and the World Wildlife Fund (WWF).
According to WWF, the standards for certifying shrimp aquaculture products proposed by GlobalGAP, a private sector body composed of European retailers that sets standards for the certification of agriculture products, would not reduce or eliminate the key negative environmental and social impacts of shrimp farming. WWF said that the standards would not be credible because they would not be measurable and would be managed by GlobalGAP instead of an independent and credible third party. WWF also noted that the standards would not be finalized based on consensus from multiple stakeholders.
For similar reasons, WWF is also concerned about standards being developed by the Global Aquaculture Alliance (GAA), an industry trade association funded by the shrimp industry. WWF says, “The GAA standards are not being created through a transparent, consensus building process and they are going to be managed by the Aquaculture Certification Council, which is affiliated with GAA and not a neutral third party entity.”
“To be accepted by consumers and the public as a whole, the standards need to be independently verifiable,” said Jose Villalon, director of the Aquaculture Program at WWF, an organization that has helped develop a wide range of standards and certification programs. “The standards cannot be created by industry for industry.”
WWF is the catalyst for a series of species-specific roundtables, called Aquaculture Dialogues that consist of multiple stakeholders who are developing standards for certifying ten aquaculture species: shrimp, tilapia, pangasius, salmon, trout and five types of mollusks. The majority of the standards are expected to be finalized in the next 18 months. Once developed, the standards will be given to a new or existing third party certification entity to manage—an essential move to ensure success, given that conflicts of interest or the perception of conflicts don’t exist when a third party entity is involved.
Information: Jill Schwartz, World Wildlife Fund, 1250 24th Street, NW, Washington, D.C. 20037-1193 USA (phone 202-822-3458, cell 202-290-6526, email email@example.com, webpage www.worldwildlife.org).
In a rebuttal to the WWF statements, GAA said:
“We recognize that standards and the standards-setting process needs to be credible and needs to involve objectivity and transparency. That’s why we recently created a 12-member standards oversight committee to help in both governance and the process. GAA made this decision based on input we received from many NGOs [non-governmental organizations] such as WWF. Going forward, NGOs will play a key role in our standards-setting process, so will other important stakeholders such as academic/regulatory agencies and industry. That is how it should be,” said GAA President George Chamberlain and GAA Executive Director Wally Stevens in a prepared statement. “There is an urgent need for harmonized standards, given the confusing and conflicting array of schemes and programs in existence today. We support this harmonization and are working closely with GlobalGAP to find ways to bring our respective programs closer together.”
“WWF has suggested that BAP standards are compromised by the fact that they are certified by the ACC. The implication is that ACC is not a third-party organization since it was originally founded by GAA. Nothing could be further from the truth. ACC today stands alone as an independent organization with its own directors and officers whose sole focus is to train and accredit third-party certifiers and auditors. ACC is in the process of achieving ISO Guide 65 certification as an internationally accredited third-party certification body.”
“In the interest of further involving stakeholders in the BAP program, GAA is soliciting public comments on the proposed new standards development process through a page on the organization’s website at http://www.gaalliance.org/comment3.html. The comment page includes an electronic comment form as well as a downloadable file that outlines how the standards oversight committee would function in coordination with GAA’s board and the BAP technical committees that draft standards. The 60-day comment period will end December 31.”
“While GAA has always sought input from a broad range of stakeholders in the development of its standards, it has come to recognize the importance of formalizing this process in a more structured and transparent manner.”
Nominations for standards should be emailed to BAP Standards Coordinator Daniel Lee at firstname.lastname@example.org or faxed to +44-0-1248-716729. Appointments are expected to be made during the first quarter of 2008.
Information: George Chamberlain, Ph.D., President, Global Aquaculture Alliance, 5661 Telegraph Road, Suite 3A, St. Louis, MO 63129 USA (phone 314-293-5500, fax 314-293-5525, email email@example.com, webpage www.gaalliance.org).
Sources: 1. World Wildlife Fund. News Release. Proposed Standards Would Not Address Market Demand for Sustainable Farmed Shrimp/World Wildlife Fund Voices Concerns about GlobalG.A.P. Standards. November 8, 2007. 2. Seafood Currents (an online newsletter from Seafood Business, www.seafoodbusiness.com). WWF blasts GAA, GlobalGAP certification programs (http://divcom-seafood.informz.net/admin31/content/template.asp?sid=5369&ptid=163&brandid=3138&uid=
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