DOI: 10.1111/are.13473
ORIGINAL ARTICLE
Effects of rearing temperature on growth and survival of larval sablefish (Anoplopoma fimbria) Matthew A Cook
| Jonathan S F Lee
| Kenneth M Massee | Thomas H Wade |
Frederick W Goetz Environmental and Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Manchester Research Station, Port Orchard, WA, USA Correspondence Matthew Cook, NOAA Manchester Research Station, Port Orchard, WA, USA. Email:
[email protected]
Abstract The effects of three different rearing temperatures (12, 15 and 18°C) on growth and survival of sablefish larvae (Anoplopoma fimbria) were examined from 5 days poststocking to weaned subjuveniles. First-feeding larvae were stocked into 960-L circular tanks at a density of 15 larvae/L (n = 3 per temperature treatment). Feeding, increases in light and water flow and other changes during the experiment were based on a degree-day (°Cday) schedule to adjust for time and temperature. The larvae were weaned on calendar day 41, 34 and 30 in the 12, 15 and 18°C treatments respectively. Survival to weaning was greater at 15 than 12 or 18°C. Calendar day and degree-day length and dry weight were greater in the 18°C treatment. The larvae were weaned 7 days earlier at 15°C and 11 days earlier at 18°C compared to larvae at 12°C. Sablefish larvae can be reared at 15°C with faster growth and good survival compared to 12°C and at an approximately 17% reduction in cost and labour. Sablefish grew even faster but had higher mortality rates at 18°C compared to 15°C. Results from genotyping strongly suggest that there is a genetic basis for performing differentially at varying rearing temperatures and would also suggest that selection for faster growth and higher survival could be accomplished in a broodstock programme. KEYWORDS
cannibalism, early weaning, fast growth, larvaculture, Northeast Pacific
1 | INTRODUCTION
sablefish as a culture species; however, bottlenecks in larval rearing, including a lack of reliable rearing protocols, are slowing the expan-
Sablefish (Anoplopoma fimbria), also known as black cod or butterfish,
sion of sablefish aquaculture. In the hatchery, temperature has a
is a high value fish found along the Pacific coast from California to
direct effect on every stage of fish development. For developing lar-
Alaska (USA) where they are targets of a restricted commercial and
vae, temperature influences the rates of enzymatic reactions that
recreational fishery. Although sablefish juveniles have been reared
drive activity and growth (Hochachka & Somero, 2002). Temperature
from eggs in captivity (Clarke, Jensen, Klimek & Pakula, 1999; Cook
can influence sex ratios (Navarro-Martin, Blazquez, Vinas, Joly &
et al., 2015; Whyte, Clarke, Ginther, Jensen & Townsend, 1994), it is
Piferrer, 2009) and can have downstream effects on muscle fibre
not always possible to consistently raise large numbers of healthy
size and number, flesh firmness (Campos et al., 2013; Lee et al.,
juveniles from eggs. There is a worldwide market for sablefish and a
2017; Sabate, Sakakura, Shiozaki & Hagiwara, 2009) and deformities
strong interest in the United States, Canada and Korea to develop
and survival (Seikai et al. in Van Maaren & Daniels, 2001; Abdel
---------------------------------------------------------------------------------------------------------------------------------------------------------------------Published 2017. This article is a U.S. Government work and is in the public domain in the USA Aquaculture Research. 2017;1–9.
wileyonlinelibrary.com/journal/are
|
1
2
|
COOK
ET AL.
et al., 2004; Tsuji, Abe, Hanyuu, Kuriyama & Tsuchihashi, 2014).
Water was greened prior to stocking larvae and kept green dur-
Temperature may also indirectly affect larval growth and behaviour in
ing the study using a 4:1 ratio of Instant Algaeâ, Nanno 3600TM,
the following ways. Water viscosity decreases as temperature
Nannochloropsis sp. paste (Reed Mariculture, Campbell, CA, USA) and
increases which may reduce the energy required for swimming (Green
food-safe, green dye (Liquid Color Green Shade, ESCO Foods, Inc.
& Fisher, 2004; Hunt von Herbing, 2002). Temperature may also influ-
San Francisco, CA, USA). The mixture was pumped from a refriger-
ence the swimming velocity of rotifers and Artemia with greater swim-
ated hopper into a computer-controlled, automated valve system
ming velocity at higher temperatures (Larsen, Madsen & Riisgaerd,
that continuously delivered the mixture to each tank. All study tanks
fera, Pascual & Olivares, 2005). Thus, increased temperatures 2008; Yu
were also given a ration of rotifers prior to stocking (10 rotifers/ml).
may make live feeds more active and thus more visible to larvae, how-
Larvae were temperature adjusted from ~5 to 12°C over a 24 hr
ever, higher temperatures may also increase live feed metabolism mak-
period in the incubation silos prior to stocking into the study tanks.
ing them less nutritious. For all of these reasons, temperature should
After stocking, all tanks were held at 12°C for the first 96 hr. Water
be highly controlled in the laboratory and hatchery to manage labour
for the 15°C treatment was increased to 15°C between 96 and
and resources and to produce healthy fish quickly. In the northeast Pacific, young, wild sablefish experience a range of water temperatures during development, from 3.8 to 6°C as eggs,
120 hr poststocking. Water for the 18°C treatment was increased to 18°C between 96 and 144 hr poststocking. On calendar day 7, all treatments were at the desired study temperatures.
to >22°C in surface waters as young juveniles (Alderdice, Jensen &
All scheduled changes in feed type and amounts, lighting and
Velsen, 1988; Sogard & Olla, 2001). Sogard & Olla (2001) found that
water flow increases and green water concentration changes were
growth rates at moderate temperatures (12–13°C) for sablefish are
based on protocols for rearing sablefish larvae at 12°C (Cook et al.,
notably high for a cold-water species. They also found that growth
2015) and adjusted for °Cday for the 15 and 18°C treatments (Rus-
rates of early juveniles increase from 6 to 16°C then remain con-
selle, Wilhelm, Olson & Power, 1984). For example, at 12°C, the
stant between 16 and 20°C. However, growth rates declined signifi-
change from rotifers to enriched Artemia occurred on calendar day 20
cantly at 22 and 24°C. Although sablefish develop within a relatively
or °Cday 240. At 15°C, the change to enriched Artemia occurred on
wide range of temperatures, control of temperature in the hatchery
calendar day 17 or °Cday 237 and at 18°C, the change to enriched
is very important during early sablefish development (Alderdice et
Artemia occurred on calendar day 15 or °Cday 231. We hypothesized
al., 1988; Clarke & Pennell, 2013; Cook et al., 2015). For example, in
that when treatments were reared on a °Cday schedule that growth
our experience, water temperatures above 6°C during egg and
(length and weight), specific growth rates (SGR) and condition factor
embryo incubation result in high mortality. In this study we reared
(CF) and survival of sablefish larvae would not be significantly different
sablefish larvae from 5 days poststocking to weaning at 12, 15 and
between treatments. If rates were not similar, it may suggest that tem-
18°C to determine if faster growth could be achieved without com-
perature has effects other than slowing or accelerating growth.
promising health and survival. All scheduled feed and green water concentration changes, and light and water-flow increases were based on our protocol for rearing sablefish larvae at 12°C (Cook
2.1 | Rearing and feeding systems
et al., 2015), and adjusted to occur on the same degree-day (°Cday)
Treatment tanks were 960-L (water volume) circular fibreglass
for the 15 and 18°C treatments.
(1200-L dimensional volume) (104 cm dia. X 152 cm deep) tanks (Fiberglass Marine Products, Shelton WA USA). Interior tank bottoms were flat and painted with white epoxy paint. Inside walls were
2 | METHODS AND MATERIALS
painted with black epoxy paint. Tanks were illuminated with one, 48” fixture with two 20-W T-10, 6500k tubes (Sylvania, Octronâ
All work was performed at the NOAA Manchester Research Station
Ecologicâ, Versailles, KY, USA) hung 70 cm above the water surface.
(Port Orchard, WA USA). Wild-caught adult female and male sablefish
Seawater (28.5 ppt) was drawn from Puget Sound, Washington
were collected off the coast of Washington State (USA) and held in our
(USA), and was UV sterilized and filtered down to 1.0 lm. The
laboratory at 6°C. Hydrated females, ready for spawning, were anes-
incoming seawater (~8°C) was heated to 12, 15 or 18°C using
thetized using tricaine methanesulfonate (MS-222) (240 mg/L; Argent
heated glycol and separate heat exchangers for each temperature
labs, Redmond, WA, USA) and gently strip spawned by hand. Eggs were
system. The temperature of each study tank was continually moni-
fertilized on site at a ratio of 1 ml of milt added directly to 200–400 ml
tored in real time and adjustments were made to maintain tempera-
of eggs (dry fertilization) and incubated at 5°C for ~46 days. Eggs from
tures within 0.5°C throughout the study. The air temperature in
five different male:female crosses were hatched and incubated accord-
the laboratory was maintained at 15°C.
ing to methods described in Cook et al. (2015). Equal numbers of larvae from the five crosses were stocked into each of the nine, 960-L treatment tanks at 15 larvae/L (~15,000 larvae per tank). All larvae were
2.1.1 | Rotifers
enumerated two to three calendar days postweaning. Survival was cal-
Rotifers were cultured as described in Cook et al. (2015). Larvae
culated at the end of the trial for each treatment tank. Survival (-
were fed rotifers from stocking to day 17, 15 or 13 dps (days post-
%) = 100 9 (final number/initial stocking number).
stocking) in the 12, 15 or 18°C treatments respectively. Rotifers
COOK
|
ET AL.
3
were fed to tanks by hand two times daily (09:00 and 16:00) and
were counted every 30th second. The strike and larval count data
once overnight (23:00) via a computer-controlled automatic feeder.
were averaged across all 30-s periods within each date for each
Rotifers were enriched with Ori-Green (Skretting, Tooele, Utah, USA)
tank. Subjective observations of larvae behaviour (feeding, swimming
for the 2-day feedings following the manufacturers’ recommenda-
and interaction) were made routinely and noted.
tions and Algamac 3050 (Aquafauna Bio-Marine, Inc., Hawthorne, CA, USA) for the overnight feeding. All tanks were fed at a rate of 7.5 rotifers/ml for the 2-day feedings and 15 rotifers/ml for the
2.2.2 | Development
overnight feeding. On °Cday 216, the rate for the day feedings was
For sablefish, the development of large pigmented pectoral fins is
increased to 11 rotifers/ml.
considered progress towards metamorphosis and a milestone during development at a point of rapid growth. Thus, the percentage of lar-
2.1.2 | Artemia nauplii
vae from each treatment with large pigmented pectoral fins was
Artemia were prepared as described in Cook et al. (2015). Artemia
were assessed under a stereoscope for pectoral fin pigment.
determined at 19 dps. Ten randomly selected larvae from each tank
nauplii (48 hr from hatch) were held in 370-L cone bottom cylinders and enriched for 12 hr at 72°F with Algamac 3050 following the manufacturers’ recommendations. Larvae were fed enriched Artemia nauplii from day 17 to 41, day 15 to 35 and day 13 to 30 dps in the
2.2.3 | Length, weight, specific growth rate and condition factor
12, 15 or 18°C treatments respectively. Artemia nauplii were fed out
All larvae were enumerated two or three calendar days postweaning.
by hand two times daily (09:00 and 16:00) and overnight (23:00) via
During larval rearing, 10 larvae were randomly netted from the tank
a computer-controlled automatic feeder. Initially, all tanks were fed
and measured (tip of the maxillary to the tip of the notochord)
at a rate of 1.0 nauplii/ml for the 2-day feedings and 1.5 nauplii/ml
weekly for the first 3 weeks using a stereoscope and a micrometre
for the night feeding. On °Cday 372, the rate for the 2-day feedings
and measured to the nearest hundredth of a millimetre using a stere-
was increased to 1.5 nauplii/ml.
oscope camera and digital analysis software (INFINTY, Luminara Corporation, Ottawa, Ontario, Canada). When larvae became too large
2.1.3 | Artificial feeds
for the micrometre they were measured (total length, TL) to the nearest 0.25 mm with a ruler. On day 5 poststocking, 30 larvae were randomly netted from each tank and combined as one sample per
Cofeeding with artificial feed began in each treatment midway dur-
tank for dry weights. The pooled larvae were anesthetized, placed
ing the Artemia feeding stage. Weaning was accomplished by a grad-
on a screen, rinsed with fresh water and wicked dry by placing a
ual increase in dry feed amounts and frequency combined with a
paper towel against the screen behind the larvae. The sample was
gradual decrease in the frequency of Artemia nauplii fed out and
placed onto a pre-weighed sheet of drying paper and placed in a
takes approximately 14 days at 12°C. Larvae were first offered Oto-
drying oven (60°C) for 24 hr. On all other sampling, 10 larvae from
TM
A, followed by sizes B1, B2 and C1 (Reed Mariculture, USA
each tank were pooled and weighed to conserve larvae during the
Campbell, CA, USA). At weaning, larvae were eating OtohimeTM C1
study. The following equations were used to compare SGR and CF
and BioVita 0.6-mm pellet (BioVita, Bio-Oregon, Longview WA,
between treatments for °Cday and calendar day.
hime
USA). Artificial diets were initially fed by hand three times per day (10 g/feeding). Timer-controlled shaker feeders were later employed as the amount and frequency of feeding increased during weaning.
1. Specific growth rate weight (SGR, %/day) = 100 (ln(final weight(ln)initial weight))/days. Weight is in dry milligrammes and length is TL in millimetres.
2.2 | Analysis 2.2.1 | Strike behaviour A downwards-pointing camera (MicroVideo MVC2000WP-LED, Micro Video, Products, Bobcaygeon, Ontario, Canada) was hung
2. Condition Factor (CF) = (Weight (/Length3)*1000. Weight is in dry milligrammes and length is TL in millimetres.
2.2.4 | Genetics
above the tank with the lens touching the water surface. A 24-
To determine if family was a variable, samples were taken at the end
gauge, plastic-coated wire was shaped into a 6.5-cm ring and hung
of the trial from each treatment to determine the contribution of
15.0 cm below the camera. Only larvae that were above the ring
each cross in the surviving progeny. For genetic analysis, 200 larvae
and had any body part within the ring was analyzed. Behaviour was
from each of the three treatments were randomly collected, eutha-
recorded for 5-min per tank, once per week for 4 weeks. From the
nized and placed in ethanol. To obtain DNA for genotyping, approxi-
video, the number of feeding strikes, defined as the body bending
mately half of the tailfin was cut from each sablefish larvae and
into a sigmoid position then springing out to capture food, was
deoxyribonucleic acid (DNA) was extracted using the Qiagen DNeasy
recorded every 30 s and the number of larvae visible in the frames
Blood and Tissue Kit (Valencia, CA). Polymerase chain reactions
4
|
COOK
(PCR) were performed in 25 ll volumes with approximately 50 ng of
ET AL.
3 | RESULTS
DNA, 12.5 ll of Amplitaq Gold master mix (Life Technologies (LT), Foster City, CA) and microsatellite-specific primers (Table 1). The
3.1 | Survival and weaning
PCRs were carried out in a MJ Research PTC-225 thermal cycler (Bio-Rad Laboratories) with cycling conditions as follows: Initial
All larvae were enumerated two to three calendar days postweaning.
denaturation at 94°C for 5 min, followed by 30 cycles at 94°C for
There was a significant survival difference between treatments
30, 45 s at the specific gene primer annealing temperatures
(p = .0411) and survival was greatest in the 15°C treatment
(Table 1), 45 s at 72°C and a final elongation for 10 min at 72°C.
(7.4 2.0%) compared to the 12°C (4.7 1.0%) and 18°C treat-
Sablefish primers Afim018, Afim372, Afim009 and Afim003 were
ment (3.7 1.0%) (Table 1). Higher temperature did accelerate
from Rondeau et al. (2013) and AFI11 and AFI5 were from McCra-
growth and development in the 15 and 18°C treatments and shorten
ney, Saski and Guyon (2012).
the number of calendar days to weaning compared to the 12°C
For reaction analysis, 9.75 ll of Hi-Di formamide and 0.25 ll of
treatment. Sablefish larvae were fully weaned on calendar days 41,
Genescan-500 LIZ size standard (LT) were combined with 1 ll of
34 or 30 in the 12, 15 and 18°C treatments, respectively, following
PCR product. The reaction was incubated at 96°C for 3 min for ther-
scheduled weaning dates.
mal denaturation and then immediately placed into a
20°C freezer
to cool. An ABI 3730 DNA analyzer was used to run the PCR prod-
3.2 | Strike behaviour
ucts and results were analyzed using Genemapper v4.1 (LT).
Strike behaviour was significantly different among treatments (p = .0115) when not adjusted for °Cday, with greater strike rates in
2.2.5 | Statistics
the 15 and 18°C treatments for weeks 1, 2 and 3 and lower strike rate
Treatment comparisons for final degree-day growth (length, weight,
at week 4 (Figure 1). There were no significant differences on strike
SGR and CF), survival and time to weaning were made with
behaviour for date (p > .05) and the interaction of date and tempera-
ANOVA and Tukey’s Multiple Comparison Test at a significance
ture was not significant (p > .05). While there were no significant dif-
level of (p < .05). A Kruskal–Wallis test followed by Dunn’s postt-
ferences in growth on sample days 5, 12 and 19, strikes per 30 s were
est was used when data did not meet the normality requirement
greater at 15 and 18°C on days 8, 15 and 22 (Figure 1).
for ANOVA. Values presented are means SEM. The statistical software used was XLSTAT (New York, NY USA). Strike behaviour
3.3 | Fin development, larvae length and dry weight
and calendar day growth (length, weight, SGR and CF) were com-
For calendar day length and weight there was a significant effect of
pared with a mixed model and Tukey’s Multiple Comparison Test at a significance level of (p < .05) using JMP statistic software
date (p < .0001) and date X temperature interaction (p < .0001). Cal-
(SAS
are
endar day differences in length and weight were not significant
means SEM. Tank was a random factor and the effect of tem-
(p > .05) on 5, 12 and 19 dps between temperature treatments. Sig-
perature, date and temperature X date interaction was tested.
nificant (p < .05) calendar day differences in length and weight
Genotyping was completed using Probmax v4.1 (Danzmann, 1997)
occurred on calendar day 26 (Table 2, Figures 2 and 3). Although
and assignment of at least 93% of the progeny to the five crosses
length and weight were not significantly different on calendar days
was accomplished using six loci.
5, 12 and 19, the percentage of sampled larvae with large,
Institute
Inc.
Cary,
NC,
USA).
Values
presented
T A B L E 1 Final dry weight, length, SGR, survival and day to wean for sablefish larvae Day/°CDay
12°C 45/540
15°C 37/537
18°C 33/555
Day/°CDay
41/492
34/477
30/501
Final sampling day
cal
Weaned
cal
4.7 1.0%abc
Survival Length (mm)
29.63 3.3a
Weight (mg)
30.41 3.28
a
7.4 2.0%ac
3.7 1.0%bc
29.94 0.49ab
34.14 1.84b
32.60 1.52
53.87 8.16b
ab
Day
15.64 0.34%a (45)
19.12 0.14%b (37)
23.42 1.14%c (33)
Weight SGR °CDay
0.88 0.04% (540)
0.89 0.01% (537)
0.96 0.07% (555)
Day
2.53 0.11
a
3.06 0.10
a
3.87 0.34b
Length SGR °CDay
0.29 0.02
a
0.30 0.07
ab
0.40 0.04b
Weight SGR
Length SGR
cal
cal
CF final °CDay
11.51 0.41a
12.13 0.14a
13.31 1.00b
SGR, specific growth rate. Data are means (n = 3) SEM. Means in a row with different superscripts are significantly different (p < .05) as determined by ANOVA and Tukey’s comparison of mean values.
COOK
|
ET AL.
5
0.6 Strikes per larva per 30 seconds
12 degrees
F I G U R E 1 Strikes per larvae per 30 s. Strike behaviour was noted as S-shaped body posture. Observations were made every 30 s for 8 min. The number of Sshaped larvae was noted. Bars are means SEM (n = 3)
0.5
0.4
15 degrees 18 degrees
0.3
0.2
0.1
0 8
15
22
29
Calendar day
pigmented pectoral fins was significantly greater (p < .0001) on cal-
higher at 18°C (23.42 1.14%) than 15°C (19.12 0.14%), or 12°C
endar day 19 in the 18°C treatment (71.0 11.0%) (p < .0001)
(15.64 0.34%) (Table 1 and 2). Final °Cday-adjusted dry weight
compared to larvae in the 15°C treatment (22.7 3.0%) and 12°C
SGR values were not significant (p > .05) between treatments, how-
treatment (p < .0001) (2.0 0.0%) (Figure 4). Final calendar day and
ever, it was highest in the 18°C treatment. Final °Cday-adjusted SGR
final °Cday lengths were significantly greater in the 18°C treatment
length values were significantly higher (p < .05) between treatments
(p < .05). Final dry weight was greatest in the 18°C treatment
and highest in the 18°C treatment (Table 1).
(p = .0331)
(53.9 14.1 mg),
which
was
significantly
greater
(p = .0413) than in the 12°C treatment (30.0 5.7 mg) but not the 15°C treatment (32.6 2.6 mg) (Tables 1 and 2, Figures 5 and 6).
3.6 | Genetics Over the three temperature treatments, approximately 95% of the lar-
3.4 | Condition factor
vae could be assigned to one of the five initial male:female crosses using six microsatellite loci. Fish in the 12°C treatment had the most
For calendar day CF there was a significant effect of date (p < .0001)
homogenous representation of the five crosses, with all five crosses
and date X temperature interaction (p = .0002). On calendar day 33
being represented at ≥10% and only one cross (5) being dominant
poststocking, the 18°C treatment CF was significantly greater
(~32%). However, in the 15°C treatment only four crosses were repre-
(p = .0014) (13.31 1.00) than the 12°C treatment (10.68 0.31)
sented at 10% or greater and two crosses (1, 5) dominated. From 12°C
but not the 15 degree treatment (12.77 0.50) (Table 2).
to 15°C the representation of one cross (4) doubled from 10 to 20%,
There was a significant effect of temperature on °Cday adjusted
while the representation of another cross (2) dropped from 20% to
CF (p = .0003). Final CF was significantly greater in the 18°C treat-
10%. At 18°C there were only three crosses represented at ≥10% and
ment (p = .0005) (13.31 1.00) than in the 15°C (12.13 0.14)
the same two crosses (1, 5) that were dominant at 15°C were also
and 12°C (11.59 0.41) treatments (Tables 1 and 2).
dominant at 18°C (~32% and ~35%) (Figure 7).
3.5 | Standard growth rate (SGR)
4 | DISCUSSION
For calendar day SGR length there was a significant effect of date (p < .0001) and date X temperature interaction (p = .0059). For cal-
We examined the effects of rearing temperature (12, 15 and 18°C)
endar day SGR weight there was a significant effect of date
on growth and survival of sablefish larvae from first feeding to the
(p < .0001) and date X temperature interaction (p = .0496). Final cal-
weaned subjuvenile stage. Rearing at 15°C resulted in faster growth
endar day SGR weight values were significantly different between
and better survival than at 12°C. In the hatchery, fast growth at
treatments (p = .0006) and greater in the 18°C treatment (Table 1).
every stage of development is economically beneficial (Pedersen,
Final °Cday SGR length values were also significantly different
1997). Although sablefish experience a range of temperatures as
between treatments (p = .0006) and greater in the 18°C treatment
they grow in the wild, precise temperature control appears to be
(Table 1). Calendar day SGR values (dry weight and length) were not
very important during sablefish egg, embryo and larval development
significantly different (p > .05) until sampling day 26 (Table 2). Final
(Clarke & Pennell, 2013; Cook et al., 2015). Temperature has imme-
calendar day SGR dry weight values were significantly (p < .0001)
diate effects on larval growth and behaviour and can also cause
6
|
COOK
ET AL.
T A B L E 2 Calendar day growth and condition of sablefish larvae reared at 12, 15 or 18°C over 45 days Days
Temperature °C
0–5
0–12
0–19
0–26
0–33
0–37
0–45
Length, TL (mm) 12
9.50 0.06
10.67 0.07
12.01 0.24
14.48 0.56a
19.14 0.90a
15
9.66 0.05
10.50 0.13
12.07 0.32
16.96 0.73
22.79 0.89a
18
9.49 0.09
10.35 0.21
12.14 0.21
18.95 1.01b
nd
1.27 0.16
2.44 0.31a
7.67 1.09a 15.25 2.19a
ab
a34.14
b29.63
na ab29.94 0.49
1.84b
0.85
na
na
na
Dry weight (mg) 12
0.026 0
15
0.028 0.002
nd
1.34 0.17
4.89 0.71
18
0.023 0.002
nd
1.58 0.11
8.19 1.38b
12
2.99 0.07
nd
7.23 0.57
7.89 0.01a
10.68 0.31a
15
3.02 0.27
nd
7.58 0.88
9.86 0.32
12.77 0.50a
18
2.73 0.37
nd
8.69 0.52
11.82 0.27b
b a13.31 1.00
5–19
5–26
5–33
nd
11.30 0.91
10.65 0.62a
a
a53.87
b30.41
na ab32.60
8.16b
1.52
3.28
na
na
na
Condition factor
Days
ab
b11.59
na b
b12.13
0.14
0.41
na
na
na
5–37
5–45
Dry weight SGR 12
na
15
na
nd
11.17 0.63
13.59 0.86a
18
na
nd
13.59 1.18
16.86 1.03b
12.05 0.52a
a23.42
c15.64
na
14.28 0.62a
b
b19.12 0.14
1.14b
0.34
na
na
na
SGR, specific growth rate; TL, total length. Values are mean SEM. Means in a column containing different superscript letters are significantly different (p < .05) as determined by a mixed-model ANOVA and Tukey’s post hoc HSD test. Values in bold are final degree-day. Values in bold with different subscript letters are significantly different (p < .05) as determined by ANOVA and Tukey’s post hoc HSD test.
38
0.07
33
12°C 15°C 18°C
0.05 0.04
Length (cm)
Dry weight (g)
0.06
0.03
12°C 15°C 18°C
28 23 18
0.02 13
0.01
8
0 5
19
26
33
37
45
Calendar day F I G U R E 2 Calendar day average dry weight (g) of 10 larvae from each treatment (n = 3)
5
12
19
26
33
37
45
Calendar day F I G U R E 3 Calendar day average length (mm) of 10 larvae from each treatment (n = 3)
delayed or downstream effects such as deformities, skewed sex
to occur on a specified °Cday, it was not certain that larvae would
ratios and undesirable changes to fillet quality. In the hatchery and
actually follow the compressed feeding and weaning schedule. Due
laboratory, temperature can also indirectly impact the physical envi-
to increased activity and metabolic demand, rearing at higher tem-
ronment in the tank (Hunt von Herbing, 2002) and influence prey
peratures does not always result in faster growth and larger fish.
swimming activity (Larsen et al., 2008).
Higher metabolism due to increased temperature without enough
Larvae were weaned on calendar days 41, 34 and 30 in the 12,
food can lead to reduced growth (Sogard & Olla, 2001). For example,
15 and 18°C treatments respectively. For sablefish, weaning is an
sea bass growth may be delayed at a rearing temperature of 19°C
approximately 12-day process at 12°C in which the number of Arte-
compared to rearing at 15°C (Abdel et al., 2004). Similarly, it was
mia feedings is gradually reduced and the amount of dry feeds is
possible that 18°C might delay sablefish larval development and lar-
gradually increased. Fish are considered weaned the day following
vae would not wean by the scheduled date. However, larvae in the
the last day of Artemia. Although the weaning date was scheduled
18°C treatment developed at a faster rate and appeared to be
|
ET AL.
90 80 70 Percent
60 50 40
b
30 20
c
10 0
12°C/°D228
15°C/°D267
18°C/°D305
Temperature/Degree day F I G U R E 4 Calender day per cent of larvae with large pigmented pectoral fins. Bars are mean SEM (n = 3). Bars with different letters indicate a significant difference between treatments (p < .05)
7
40
a Percent of treatment total (200)
COOK
30
Cross 1 Cross 2 Cross 3
20
Cross 4 Cross 5 10
Unassigned
0 18°C
15°C
12°C
F I G U R E 7 Percentage of crosses represented at the end of the temperature trial. Unassigned crosses are those for which the parents could not be determined. Each temperature treatment was initially stocked with 20% from each of five crosses
0.06
12°C 15°C 18°C
Dry weight (g)
0.05 0.04
Strike behaviour followed a pattern in which larvae reared at higher temperatures appeared to strike more often up to day 22 poststocking. Strike behaviour changes over time as feeding methods and
0.03
swimming behaviour change. Older larvae rely less on strike beha-
0.02
viour and appear to swim at the prey or maintain position in the water current and eat prey as they get close. By week 4, larvae in
0.01
the 15 and 18°C treatments had begun to eat dry diets and were no longer using the strike method for feeding. While there were no sig-
0 50
250
450
Degree °C Days
nificant differences in growth on sample days 5, 12 and 19, strike rates were greater at 15 and 18°C on days 8, 15 and 22 (Figure 1).
F I G U R E 5 Degree day average dry weight (g) of 10 larvae from each treatment (n = 3)
Growth between the treatments was not different between stocking and calendar day 19; however, on calendar day 19, 70% of the larvae from the 18°C treatment had developed black pectoral fins compared to 22% at 15°C and 2% at 12°C. Development of
38
black, paddle-like pectoral fins is considered progress towards meta-
Length (mm)
33 28
12°C
morphosis and larvae that reach this stage have a high chance of
15°C
surviving past weaning. Although length and weight were not significantly affected by temperature to 19 dps, other developmental mile-
18°C
stones were being reached sooner and larvae were also attempting
23
to eat more at 18°C strongly suggesting that temperature had other 18
effects on larval behaviour and development. The production of live feeds (rotifers and Artemia) is expensive
13
and labour intensive. Increasing the temperature during weaning can potentially reduce the weaning period and the cost of live feed
8 50
250
450
Degree °C Days F I G U R E 6 Degree day average length (mm) of 10 larvae from each treatment (n = 3)
(Puvanendran, Burt & Brown, 2006). The difference between 12 and 18°C in our study was a 25% reduction in the amount of rotifers and Artemia needed and a significant reduction in time and labour. Results from other studies (Appelbaum, 1989; Puvanendran et al., 2006) have suggested that the ability of larval fish to accept dry
consuming mostly dry diet by day 28, 2 days earlier than the sched-
feed may be enhanced at higher temperatures. This is partly due to
uled wean date. Strike data suggest that sablefish larvae were
an increasing energy demand due to the elevated metabolic rates at
attempting to eat more often at higher temperatures.
higher temperatures. Near weaning, cod larvae oriented towards,
Strike behaviour was significantly different among treatments,
and consumed more dry feed, at 11.5°C than at 7.5°C, however,
with higher strike frequencies in the 15 and 18°C treatments during
growth rate and survival between treatments were not significantly
weeks 1, 2 and 3 and less strikes per second at week 4 (Figure 1).
different (Puvanendran et al., 2006). In this study, based on °Cday,
8
|
COOK
ET AL.
weaning and the last day for Artemia feeding was calendar day 30 in
In the ocean, after being conceived at great depths, developing
the 18°C treatment. However, by calendar day 28, larvae appeared
sablefish embryos slowly ascend where they begin feeding as larvae in
to be consuming less Artemia and aggressively feeding at the surface
warmer surface waters. Thus, sablefish eggs, yolk-sac embryos and lar-
on dry diet in the 18°C treatment. The greater interest and earlier
vae encounter a range of temperatures as they develop from as low as
than anticipated weaning may partly explain why larvae were signifi-
3.8°C as eggs and yolk-sac embryos (Mason, Beamish & McFarlane,
cantly heavier at weaning in the 18°C treatment.
1983) to 22°C near the surface in the northeast Pacific as larvae and
Cannibalism may also partly explain why larvae in the 18°C were
young juveniles (Sogard & Olla, 2001). Ocean surface temperatures,
larger at final sampling. Cannibalism can be a problem with sablefish
along with other variables, may determine sablefish year class strength.
larvae and cause significant mortality. Cannibals may weigh more at
Sigler, Rutecki, Courtney, Karinen and Yang (2001) analyzed 40 years
sampling if they have recently consumed a cohort and this may affect
of data by McFarlane and Beamish (1992) and others and found sable-
weight measurements. Furthermore, cannibals may eat the smaller fish
fish recruitment was above average in 61% of the years when tempera-
in the tank, which would increase the average weight of the survivors
ture was above average, but recruitment was above average in only
(Barron et al., 2012). Although not quantified in this study, cannibalism
25% of the years when temperature was below average. McFarlane
may have been higher at 18°C. In the 18°C treatment larvae appeared
and Beamish (1992) suggested that greater recruitment might have
more aggressive and there was also greater size disparity (data not
been a result of increases in cold-water-driven nutrient upwelling and
shown) approaching weaning compared to the 12 and 15°C treat-
copepod abundance associated with warmer surface ocean currents. In
ments. Aggressive behaviour at higher temperatures has been reported
the wild, predation mortality decreases with increasing body size
with the larvae of other marine species (Sabate et al., 2009; Tandler
(Peterson & Wroblewski, 1984), thus rapid larval growth is important
et al., 1989). We have reduced cannibalism (and slowed growth) by
to survival and recruitment. Although not specifically stated as a factor
reducing the temperature in tanks of weaned sablefish larvae from 12
by McFarlane and Beamish (1992), greater recruitment during some
to 8°C. Thus, at rearing temperatures above 12°C, size grading should
years may also have occurred as a direct effect of above average tem-
be done midway between the start of Artemia and the projected wean-
peratures increasing the growth rate of sablefish larvae. Thus, the com-
ing date to reduce cannibalism. At 15 and 18°C, cannibalism begins
bination of temperature-accelerated growth rate and the indirect
soon after larvae start feeding on Artemia compared to 12°C where it
effects of temperature on prey quality and abundance may drive sable-
starts closer to weaning. At higher temperatures, size grading should be
fish year class strength. The results of this study suggest that in years
done as soon as larvae can tolerate handling.
with different surface water temperatures, there may be strong selec-
Growth may also have been accelerated at higher temperatures
tion for genotypes that would perform better at a given temperature
because live feeds may have been more active and thus more avail-
and would thus result in year classes with very different genotypes.
able to the feeding larvae. The swimming speed of rotifers and Arte-
However, as sablefish are a long-lived species with the potential to
mia increases as temperature increases. For example, Larsen et al.
reproduce over many years, temperature effects in a given year may be
(2008) showed that a 10°C increase in temperature leads to a 37%
diluted over time unless temperature changes become directional, as
increase in swimming velocity in Artemia nauplii and 26% increase in
they appear to be as a result of global warming.
rotifer swimming velocity.
In conclusion, this study shows that sablefish larvae can be
There is likely to have been a genetic effect on size at weaning
reared at 15 and 18°C with faster growth and good survival com-
as well as some of the other factors measured in this study based
pared to 12°C. Culturing sablefish at higher temperatures signifi-
on the parentage analysis. However, as parental effects could not be
cantly reduces the amount of labour and expensive live feeds
statistically analyzed, these are only inferences at this point and will
required during the intensive larval period. Future studies may fur-
have to be specifically addressed in future studies. Larvae from five
ther refine rearing temperature protocols by testing different tem-
crosses were initially stocked in equal amounts. Thus, by chance,
perature
progeny from each cross should theoretically represent 20% of the
temperatures above 18°C. There appears to be some genetic basis
total number in the tank. However, it appeared that increasing rear-
for larval performance at the different rearing temperatures, which
ing temperature resulted in an overall decrease in the percentage of
suggests that selection for faster growth and higher survival could
progeny represented from each cross. For example, only in the 12°C
be accomplished in broodstock programmes with this species.
changes
through
larval
ontogeny,
or
rearing
at
treatment were all of the five crosses represented above 10%. In the 15°C treatment, four crosses were represented at 10% or above and only three of the crosses were represented above 10% in the 18°C
ACKNOWLEDGMENTS
treatment. At 18°C two crosses were dominant and comprised
The authors thank Eric Samuelson and the crew of the Playboy Too
approximately ~67% of the weaned larvae. The same two crosses
for helping collect sablefish broodstock from the Pacific. We thank
represented ~53% of the weaned larvae in the 12°C treatment.
Doug Immerman for monitoring the temperature and Andrew
Overall, the genotyping results strongly suggest that there is some
Jasonowicz, William Fairgrieve, Hannah Watermann and Jose Reyes-
genetic basis for performing differentially at varying rearing tempera-
Tomassini for maintenance of larval systems during the study. We
tures and would also suggest that selection for faster growth and
thank Crystal Simchick for genetics analysis and Lynn Knapp for
higher survival could be accomplished in this species.
analysis of strike behaviour video.
COOK
|
ET AL.
ORCID Matthew A Cook
http://orcid.org/0000-0002-6043-0868
Jonathan S F Lee
http://orcid.org/0000-0002-4614-2448
REFERENCES pez-Albors, P., Valde s, O., Nortes, M. J., & GarcıaAbdel, I., Abellan, E., Lo Alcazar, A. (2004). Abnormalities in the juvenile stage of sea bass (Dicentrarchus labrax L.) reared at different temperatures: Types, prevalence and effect on growth. Aquaculture International, 12, 523–538. Alderdice, D. F., Jensen, J. O. T., & Velsen, F. P. J. (1988). Preliminary trials on incubation of sablefish eggs (Anoplopoma fimbria). Aquaculture, 69, 271–290. Appelbaum, S. (1989). Can inert diets be used more successfully for feeding larval fish? (thoughts based on indoor feeding behavior observations). Polskie Archiwum Hydrobiologii, 36(4), 435–437. Barron, J. M., Jensen, N. R., Anders, P. J., Egan, P. J., Ireland, S. C., & Cain, K. D. (2012). Effects of temperature on the intensive culture performance of larval juvenile North American burbot (Lota lota maculosa). Aquaculutre, 364–365, 67–73. Campos, C., Castanheira, M. P., Engrola, S., Valente, L. M. P., Fernandes, J. M. O., & Conceicßao, L. E. O. (2013). Rearing temperature affects Senegalese sole (Solea senegalensis) larvae protein metabolic capacity. Fish Physiology and Biochemistry, 39(6), 1485–1496. Clarke, W. C., Jensen, J. O. T., Klimek, J., & Pakula, Z. (1999). Rearing of sablefish (Anoplopoma fimbria) from egg to juvenile. Bulletin of the Aquaculture Association of Canada, St. Andrews, NB (Canada), 99(4), 11–12. Clarke, W. C., & Pennell, W. (2013). Aquaculture research and development on the Pacific coast. Bulletin of the Aquaculture Association of Canada, 110(2), 3–13. Cook, M. A., Massee, K. C., Wade, T. H., Oden, S. M., Jensen, C., Jasonowicz, A., . . . Goetz, F. W. (2015). Culture of sablefish (Anoplopoma fimbria) larvae in four experimental tank designs. Aquacultural Engineering, 69, 43–49. Danzmann, R. G. (1997). PROBMAX: A computer program for assigning unknown parentage in pedigree analysis from known genotypic pools of parents and progeny. Journal of Heredity, 88, 333. Green, B. S., & Fisher, R. (2004). Temperature influences swimming speed, growth and larval duration in coral reef fish larvae. Journal of Experiemntal Marine Biology and Ecology, 299, 115–132. Hochachka, P. W., & Somero, G. N. (2002). Biochemical adaptation: Mechanism and process in physiological evolution. Oxford; New York, NY: Oxford University Press. Hunt von Herbing, I. (2002). Effects of temperature on larval fish swimming performance: The importance of physics to physiology. Journal of Fish Biology, 61, 865–876. Larsen, P. S., Madsen, C. V., & Riisgaerd, H. U. (2008). Effect of temperature and viscosity on swimming velocity of the copepod Acartia tonsa, brine shrimp Artemia salina and rotifer Brachionus plicatilis. Aquatic Biology, 4(1), 47–54. Lee, J. S. F., Cook, M. A., Luckenbach, J. A., Berejikian, B. A., Simchick, C. A., Oden, S., & Goetz, C. A. (2017). Effects of larval temperature on long-term growth, deformities, flesh quality, and phenotypic sex of cultured sablefish (Anoploppma fimbria). Aquaculture, 479, 91–99. Mason, J. C., Beamish, R. J., & McFarlane, G. A. (1983). Sexual maturity, fecundity, spawning, and early life history of sablefish (Anoplopoma fimbria) off the Pacific Coast of Canada. Canadian Journal of Fisheries and Aquatic Sciences, 40(12), 2126–2134. McCraney, T. W., Saski, A. C., & Guyon, J. R. (2012). Isolation and characterization of 12 microsatellites for the commercially important
9
sablefish, Anoplopoma fimbria. Conservation Genetics Resources, 4(2), 415–417. McFarlane, G. A., & Beamish, R. J. (1992). Climatic influence linking copepod production with strong year-classes in sablefish, Anoplopoma fimbria. Canadian Journal of Fisheries and Aquatic Sciences, 49, 1801–1815. Navarro-Martin, L., Blazquez, M., Vinas, J., Joly, S., & Piferrer, F. (2009). Balancing the effects of rearing at low temperature during early development on sex ratios, growth and maturation in the European sea bass (Dicentrarchus labrax). Aquaculture, 296(3–4), 347–358. Pedersen, B. H. (1997). The cost of growth in young fish larvae, a review of a new hypothesis. Aquaculture, 155, 259–269. Peterson, I., & Wroblewski, J. S. (1984). Mortality rate of fishes in the pelagic ecosystem. Canadian Journal of Fisheries and Aquatic Sciences, 41, 117–1120. Puvanendran, V., Burt, A. L., & Brown, J. A. (2006). Can Atlantic cod (Gadus morhua) larvae be weaned faster onto dry feed at higher temperatures? Aquaculture, 255, 334–340. Rondeau, E. B., Messmer, A. M., Sanderson, D. S., Jantzen, S. G., R von Schalburg, K., Minkley, D. R., . . . Koop, B. F. (2013). Genomics of sablefish (Anoplopoma fimbria): expressed genes, mitochondrial phylogeny, linkage map and identification of a putative sex gene. BMC Genomics, 14, 452. Russelle, M. P., Wilhelm, W., Olson, R. A., & Power, J. F. (1984). Growth analysis based on degree days. Publications from USDA-ARS/UNL Faculty. Paper 123 Sabate, F. de la S., Sakakura, Y., Shiozaki, M., & Hagiwara, A. (2009). Onset and development of aggressive behavior in the early life stages of the seven-band grouper Epinephelus septemfasciatus. Aquaculture, 290(1–2), 97–103. Sigler, M. F., Rutecki, T. L., Courtney, D. L., Karinen, J. F., & Yang, M.-S. (2001). Young of the year sablefish abundance, growth, and diet in the Gulf of Alaska. Alaska Fishery Research Bulletin, 8(1), 57–70. Sogard, M. S., & Olla, B. L. (2001). Growth and behavioral responses to elevated temperatures by juvenile sablefish Anoplopoma fimbria and the interactive role of food availability. Marine Ecology Progress Series, 217, 121–134. Tandler, A., Harel, M., Wilks, M., Levinson, A., Brickell, L., Christie, S., . . . Barr, Y. (1989). Effect of environmental temperature on survival, growth and population structure in the mass rearing of the gilthead seabream, Sparus aurata. Aquaculture, 78(3–4), 277–284. Tsuji, M., Abe, H., Hanyuu, K., Kuriyama, I., & Tsuchihashi, Y. (2014). Effect of temperature on survival, growth and malformation of cultured larvae and juveniles of the seven-band grouper (Epinephalus septemfasciatus). Fisheries Science, 80(1), 69–81. Van Maaren, C. C., & Daniels, H. V. (2001). Effects of temperature on egg hatch, larval growth and metamorphosis for hatchery-cultured southern flounder, Paralichthys lethostigma. Journal of Applied Aquaculture, 11(1/2), 21–33. Whyte, J. N. C., Clarke, W. C., Ginther, N. G., Jensen, J. O. T., & Townsend, L. D. (1994). Influence of composition of Brachionus plicatilis and Artemia on growth of larval sablefish (Anoplopoma fimbria Pallas). Aquaculture, 119(1), 47–61. fera, M., Pascual, E., & Olivares, J. M. (2005). Factors affecting swimming Yu speed in the rotifer Brachionus plicatilis. Hydrobiologia, 546, 375–380.
How to cite this article: Cook MA, Lee JSF, Massee KM, Wade TH, Goetz FW. Effects of rearing temperature on growth and survival of larval sablefish (Anoplopoma fimbria). Aquac Res. 2017;00:1–10. https://doi.org/10.1111/are.13473
