SPAWN SIZE AND FERTILIZATION RATES FOR L. VANNAMEI

From: Steve Arce

To: shrimp@egroups.com

Sent: April 13, 2000

QUESTION:

Can anyone on the Shrimp-one list please direct me to the most current information/data (published or un-published) on average spawn sizes and fertilization rates for L. vannamei broodstock via natural mating or artificial inseminations? 

Steve Arce

sarce@oceaninstitute.org

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COMMENTS 1:

I am working on a summary of penaeid fecundity for the UJNR Proceedings (from the meeting in Maui last November), and can send the spawn size summary to you easily. I had Bill Bray review this recently and he also provided input to this, as well as other shrimp@one members. Any additions or corrections would also be appreciated.

Fecundity
Most penaeids (proposed modifications to the genus Penaeus by
Perez-Farfante and Kensley, 1997) produce from 22,000 to 1,000,000 eggs per spawn. The larger species and the larger females within a species generally produce larger numbers of eggs. Martosubroto (1974) showed that there is a direct correlation between size of the shrimp and the number of eggs per spawn. Evidence indicates multiple spawning of unablated P. setiferus (five spawns per lifetime) and at least two
spawns per season for P. setiferus, P. duorarum, P. japonicus and Metapenaeus affinis. In captivity, multiple spawning of unablated P.
japonicus and pond raised P. vannamei has been shown. In one case, an
unablated P. vannamei female spawned 19 times in seven months. Unablated P. merguiensis have been noted to spawn an average of 2.6 months in captivity compared with an average 2.8 for P. japonicus.

There are conflicting data, but wild P. vannamei generally produce
average spawns between 55,000-150,000 eggs whereas pond raised females of the same species and size produce 22,000-100,000 eggs. The larger species, such as P. monodon, can produce 700,000 to over 1 million eggs each spawn. For example, a 290-g (10.2-oz) female P. monodon  might spawn 700,000 eggs, whereas a 454-g (1-LB) female might spawn 1.4 to 1.8 million eggs each spawn (personal experience in Indonesia). Data for wild P. vannamei spawners from the Ecuadorian coast that might contradict the above. This info was presented earlier by one of the shrimp@one members and looking back at the shrimp@ one archives, the member states, "The following equation was calculated from 612 spawns (some of them were repeat spawns) from spawners with weights ranging from 27 to 80 g:  y = 3665 x + 22660  with R-squared = 0.1892. The largest spawn in this group was 621,000 eggs from a 45-g female. Pond shrimp (n=51) give similar results to wild spawners. It has been shown in most batches of wild P. vannamei spawners that there is a significant positive correlation between fecundity and spawner weight (p<0.05; p<0.001). When filling in data in the previously listed equation [eggs per spawn = (3665 x spawner weight in grams) + 22660]  it can be noticed that this equation is OK for wild broodstock, while domesticated animals produce 30% less than predicted. The latter observation is only based on 25 samples, which is not enough to draw solid conclusions."

This could indicate that lower fecundity of domesticated broodstock is
not only due to lower spawner weight, but that other factors are
involved as well. For example, Medina et al. (1996) detected an absence of fully mature oocytes in pond P. kerathurus, and Tan-Fermin (1991) reported smaller oocytes in pond ablated P. monodon. Browdy et al. (1986) reported lower eggs per spawn but equal egg production per day for P1 P. semisculatus as compared to P0.  Pond-raised broodstock may not have been fed adequately. Some managers feed their animals excellent feeds in the ponds (artificial broodstock diets and fresh diets), and often overcome this problem. In the domestication process most hatchery operations report that it generally takes three to four generations to obtain pond broodstock of equal or better quality than wild broodstock. Palacios and Racotta (1999) state that lower fecundity alone should not discourage the use of domesticated broodstock P. vannamei. Operations depending upon wild broodstock should start serious breeding programs as soon as possible and over time the benefits will become apparent. Fecundity is just one of a long list of traits to select for in a breeding program. Spawning without ablation is another. Others might be fast growth or disease resistance.

Other data available on fecundity (Peter Larkins, shrimp@one list) are:
"Domesticated stocks from Colombia (Wt 37g) eggs/female 105,000 (n=25); Wild stocks from Panama (pond raised from wild nauplii kept in maturation tanks with Wt 29.5g) eggs/female 116,000 (n=25); and Ecuadorian (wild broodstock kept in maturation tanks with Wt 60g) eggs/female 230,000 (n=130)."

Other references showing higher egg numbers with larger animals are:
Emmerson, 1980, Ottogalli et al., 1988, Hansford and Marsden, 1995,
Beard et al., 1977, Menasveta et al., 1993, and Wyban et al., 1987.

Preston et al. (1999) showed that wild kuruma shrimp broodstock produced about the same number of eggs as equal sized domesticated kuruma shrimp broodstock, but the survival of the domesticated stock larvae was half that of wild. They found that it would take 12 domesticated brood to produce enough postlarvae to stock a one hectare pond, whereas, it would only take 6 wild brood to stock the same pond with postlarvae. They also compared the costs of postlarval production from wild and domesticated and found that to stock a one hectare pond with postlarvae, it would cost Aus$ 851 per pond with wild broodstock compared to Aus$ 390 for domesticated broodstock.  The high cost of sourcing wild brood contributed to the difference.

I do not have information on artificial insemination but suspect numbers to be lower. Bill Bray would have these numbers.
Hope that this summary helps.
I do not have full citations on all the references yet, but here are the
ones that I have:

Beard, T.W. and J.F. Wickins, 1980. Breeding of Penaeus monodon
(Fabricius) in laboratory recirculation systems. Aquaculture, 20:79-89.

Emmerson, W.D., 1980. Induced maturation of prawn Penaeus indicus. Mar. Ecol. Prog. Ser., 2:121-131.

Hansford, S.W. and G.E. Marsden, 1995.  Temporal variation in egg and larval productivity of eyestalk ablated spawners of the prawn Penaeus monodon from Cook Bay, Australia.  J. World Aquacult. Soc. 26: (4), 396-405.

Martosubroto, P., 1974, Fecundity of pink shrimp Penaeus duorarum
Burkenroad.  Bull. Mar. Sci. 24:606-627.

Menasveta, P.  et al., 1993. Aquaculture 116: 191-198.

Ottogalli, L., C. Galinie, and D. Goxe, 1988.  Reproduction in captivity of Penaeus stylirostris over ten generations in New Caledonia, Pacific Ocean. J. Aquacult. Tropics 3: 111-126.

Perez-Farfante, I. and B.F. Kensley, 1997.  Penaeoid and Sergestoid
Shrimps and Prawns of the World. (Keys and Diagnoses for the Families and Genera).  Published in France (text in English) by the Musée National d'Histoire Naturelle. 175: 1- 233.

Preston, N.P., D.C. Brennan and P.J. Crocus, 1999.  Comparative costs of postlarval production from wild or domesticated Kuruma shrimp, Penaeus japonicus (Bate), broodstock. Aquaculture Research, 30: 191-197.

Wyban, J.A. C.S. Lee, J.N. Sweeney and W.R. Richards, 1987. Observations and development of a maturation system for P. vannamei. WAS 18(3): 198-200.

Granvil Treece

gtreece@unix.tamu.edu

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COMMENTS 2 :

I notice that you asked for "fertilization rates", and yet almost everyone
has replied with "mating rates", which is something altogether different.
Which parameter were you actually interested in? Most hatcheries measure mating or spawning rates, but not many actually measure the percentage fertility of the spawns, a topic that Dr. Bill Bray has researched.
Also, data on average spawn size is almost irrelevant without the
corresponding information on the size of the broodstock.
My experience with the pond reared domesticated vannamei broodstock that I have raised and maintained under normal maturation conditions, is that our naturally mated, unablated and ablated, domesticated vannamei broodstock averaging around 45 grams (females) typically produce in the range of 120,000 - 160,000 viable nauplii per spawn. It has been more than 15 years since I actually measured the fertility rate (% of fertile eggs in each spawn), but I
seem to recall it generally varied from 60-90% in viable spawns. Our
natural spawning (mating rates) generally are on the order of 7-12% of the female population per day (when the maturation system is "healthy").

Henry C. Clifford
Technical Director
Super Shrimp Group

hcclifford@aol.com

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