Total Number of nauplii selected (million) & Nursery 12 Hatchery 5,450,000 ychaetes9,160,000
TOTAL NUMBER OF NAUPLII SELECTED (MILLION) 10,000,000 5,000,000 0 T1 L I VE L OC AL P O L Y C H A ET E S
ge Average ual individual rom weight at the day end of the ning trial 56.3
6
69.0
6
55.8
4
69.9
80.0
T2 L I VE TOP SY BAI TS SP F P O L Y C H A ET E S
69.9
69.0
70.0
Individual weight (g)
1
60.0
51.6
50.0
42.1
40.0
45.6
56.3
49.4
55.8
30.0 20.0 10.0
Figure 1. Total numbers of nauplii selected produced; T1, broodstock fed live local polychaetes (Vietnam) and T2 broodstock fed live Topsy Baits SPF polychaetes. There were 37 pairs of broodstock and the duration of the trial was 7 weeks.
For more than 30 years, Topsy Baits has performed routine sampling and testing of the polychaetes with local authorities and since 2012, they have utilised the University of Arizona’s Aquaculture Pathology Laboratory for regular testing. Their SPF status is confirmed by two independent sources, with zero pathogens detected, to date. This is the standard we must adopt for any live or fresh maturation diets.
0.0 Average individual weight from the Average individual weight at the end first day of spawning of the trial Control-M Control-F Topsy-M Topsy-F
Figure 2. Average individual weight of broodstock on day 1 to end of the trial (M=males; F=Females, Topsy = SPF polychaetes from Topsy Baits, Netherlands).
n rateMating % rate % 7.25 30.75 10.3 polychaetes 34.52
1
9,160,000
5,450,000
40 35
34.52
30.75
30 % 25 20 15 7.25
10
10.3
5 0 Maturation rate % T1 Control
Mating rate %
T2 Topsy Baits SPF live polychaetes
Farming polychaetes outside of tropical climates native to shrimp farming countries also has performance related benefits. Nereis virens, a cold-water polychaete species farmed by Topsy Baits and Delta Farms, can only be farmed in specific, cold-temperature climates (5 to 10°C). It has a significantly higher nutritional profile compared to local polychaetes found in tropical countries, such as India and Vietnam. Table 1, which highlights the nutritional profile of N. virens, shows its clear superiority across all parameters when compared to wild caught polychaetes found in India and Vietnam. This nutritional superiority of N. virens, when compared to tropical origin polychaetes, will result in an increase of the nauplii number per female (Figure 1 and 2); increase in mating and in maturation rates (Figure 3); offers better recovery after each spawning (Figure 4), increase the quality of the sperms, increase the quality of the eggs (higher hatching rate) and offer full traceability from the worms to the final shrimp post larvae.
Figure 3. Comparison on maturation and mating rate (%) between broodstock fed live local polychaetes (Vietnam) and spawners fed live SPF Topsy Baits (TB) polychaetes.
Treatment 2
(Live Topsy s - Baits SPF polychaetes)
81 17
23
90 80 70 60 50 40 30 20 10 0
81
44 15
17
23 10
Total spawns
No. of females with ≥ 1 No. of females with ≥ 2 spawn spawns Treatment 1 (Live local polychaetes - Vietnam) Treatment 2 (Live Topsy Baits SPF polychaetes)
Figure 4. Spawning of broodstock fed live local polychaetes (Vietnam) and broodstock fed live Topsy Baits SPF polychaetes. The number of weeks from the first spawning until the end of the trial (Treatment 1 = 6 weeks and Treatment 2 = 7 weeks).
January/February 2022 AQUA Culture Asia Pacific
Stephen Christensen and Florian Renault are Co-Founders of SPF Shrimp Feeds, an aquaculture feed supplier focusing exclusively on live, fresh and natural diets for both shrimp maturation and larval stages with specific pathogen free (SPF) status, tested and certified by the University of Arizona's Aquaculture Pathology Laboratory, USA. Email: info@SPFshrimpfeeds.com www.spfshrimpfeeds.com
