Temperature preference and acclimation in Poecilia sphenops (Pisces, Poeciliidae)

The preferred temperature (PT) of Poecilia sphenops (Pisces, Poeciliidae) (n = 240; 1.13 ± 0.06 g wet weight; 3.26 ± 0.88 cm standard length) from Presa Piedra Azul, Oaxaca, Mexico, was measured at acclimation temperature of 20 °C, 23 °C, 26 °C, 29 °C, 32 °C and 35 °C. The thermal preference of males was 25.5 °C in summer and 29.6 °C in winter; whereas females preferred 29 °C in both seasons. Fish held at 20 °C and 23 °C preferred temperatures 36% higher than their acclimation temperature (AT), and those held at 35 °C and 32 °C preferred 30% and 20% lower temperatures than their AT. In intermediate temperatures, no significant differences between PT and AT were found. The interval of thermal selection based on the higher (HAT) and lower (LAT) avoidance temperatures was of 10–14 °C and not different between sexes in both seasons. Knowledge of the thermal biology of P. sphenops based on the preferred and avoidance temperatures was very important in order to understand the capacity of the species to adapt to the thermal changes occurring in its habitat. Based on the results, we can recommend the use of P. sphenops in aquaculture owing to its thermal plasticity.     

Influence of temperature on growth and survival of juvenile winter flounder,Pseudopleuronectes americanus (Walbaum) reared under continuous light

Winter flounder, Pseudopleuronectes americanus, has emerged as a promising candidate flatfish for cold‐water aquaculture and restocking. Here, juveniles were reared for 8 weeks at three temperatures: 10, 15, and 20°C under 24‐hr light. All fish were imaged at stocking and at 2‐week intervals, where growth was measured as changes in standard length (S_L) and body area (B_A). By week 2, fish reared at 15 and 20°C were larger than those grown at 10°C. At weeks 4 to 6, fish at 15°C were larger than fish at 20°C. Linear regressions were used to model growth dynamics over time at each temperature. Highly significant linear growth trajectories were detected over time for S_L and B_A. S_L and B_A regressions also showed a significant difference among the slopes across temperatures, where comparing slopes showed the best temperature to rear the flounder was 15°C. Weights of fish held at 15°C and 20°C were greater than at 10°C at the termination of the experiment. Within each temperature, the growth rate of malpigmented fish was not different from that of the normally pigmented fish. Overall, growth of winter flounder was comparable to that of other commercially produced flatfish species, providing strong evidence for this flatfish species as a potential species for aquaculture.     

Effects of temperature on fertilized eggs and larvae of tawny puffer Takifugu flavidus

Tawny puffer Takifugu flavidus is a species found in China considered to have potential for aquaculture. Experiments were conducted to determine the optimal temperature for its incubation and larval culture. Fertilized eggs collected from cultured broodstocks that were induced to ovulate with a [d ‐Ala⁶‐Pro⁹‐Net]‐luteinizing hormone‐releasing hormone analogue were inseminated. The effect of temperature (19, 20, 23, 26 and 29 °C) on the hatch rate, incubation period, viability of 24 h post‐hatch larvae and total mortality rate was assessed. The effect of temperature (20, 23, 26 and 29 °C) on the growth and survival of larvae from 3 to 19 days after hatching (dah) was also assessed. The results showed that the optimal temperature for successful development of fertilized eggs ranged from 23 to 26 °C, and the highest hatch rate, the optimal viability of 24 h post‐hatch larvae and the lowest total mortality rate were all predicted using quadratic equations. The relationship between temperature and the incubation period of tawny puffer eggs was determined using the effective degree‐day model. The temperature at developmental zero (t₀) was 11.34 °C, and the sum of effective degree‐days (k) was 52.356. The survival rate of tawny puffer larvae at 20 °C was significantly lower than among 23, 26 and 29 °C, whereas the survival rate was not significantly different from that at 23, 26 and 29 °C. The larval growth rate increased rapidly as the temperature increased, showing a linear relationship in the range of temperatures investigated. The optimal temperature for larval culture ranged from 23 to 29 °C.     

Dietary Lipid Utilization by Juvenile Summer Flounder Paralichthys dentatus

The ability of juvenile summer flounder Paralichthys dentatus to utilize dietary lipid as energy, and the effect of dietary lipid on weight gain and body composition was investigated in a 12-week feeding trial. Diets were formulated to provide 55% crude protein from herring meal and casein. Menhaden oil was added to produce diets with 8, 12, 16 or 20% total lipid while providing 16.0 kJ available energy/g dry diet. The diet containing 20% total lipid supplied 16.7 kJ available energy/g dry diet due to the high levels of protein and lipid. An additional diet was included to reproduce currently available commercial diet formulations for flounder, providing 55% crude protein supplied solely from herring meal and 16% total dietary lipid. Juvenile summer flounder (initial weight 23 g) were stocked into triplicate aquaria in a closed, recirculating system maintained at 20 C. Fish were fed 2% of body weight each day divided into two equal feedings. Upon termination of the study, effects of dietary lipid on weight gain, body condition indices, and proximate composition were determined. Weight gain (96–149% of initial weight), feed efficiency ratio values (0.43–0.48). fillet yield, and whole-body composition all were unaffected by dietary lipid level. High levels of dietary lipid did increase the lipid content in the finray muscle, as fish fed diets containing 16 and 20% dietary lipid had significantly higher lipid levels than fish fed the diet containing 8% lipid. No apparent protein sparing effect of lipid was observed. These data indicate that currently available commercial feeds for summer flounder may be over-formulated and show a need for further research to determine specific and accurate nutritional information for this species.     

Ammonia nitrogen excretion in Mandarin Fish (Siniperca chuatsi) and Grass Carp (Ctenopharyngodon idellus) fed practical diets: the effects of water temperature

To understand the actual production of fish culture about the utilization of dietary protein and excreta impact on the environment between mandarin fish (Siniperca chuatsi) and grass carp (Ctenopharyngodon idellus), the study to investigate the effect of temperatures (19 ± 0.5°C, 24 ± 0.5°C and 29 ± 0.5°C) on ammonia‐N excretion in mandarin fish and grass carp under fed and fasted states was conducted. These two species were fed a practical diet containing 325.2 g kg^?1 crude protein at 3% body weight per day. The ammonia‐N excretion rate was significantly increased when temperature increased from 19 to 29°C, and a linear relationship between ammonia‐N excretion rate and temperature. The maximum ammonia‐N excretion levels of mandarin fish and grass carp were observed at 4–8 h and 2–4 h after feeding, respectively, and the minimum values for both species were observed at 24 h after feeding. Under the feeding condition, mandarin fish had a lower ammonia‐N excretion level compared to grass carp at 24°C and 29°C. The average amount of ammonia‐N excreted by mandarin fish at 24 h is significantly higher than grass carp under fasting conditions, except 19 ± 0.5°C. These results indicated that mandarin fish might make better use of protein at higher temperature than grass carp when fed practical diets in commercial production. These results of this study suggested that mandarin fish had a lower ammonia‐N excretion level compared with grass carp, making a less contribution to environmental loading in an intensive fish culture.     

Food ingestion,prey selectivity,feeding incidence,and performance of yellowtail kingfish Seriola lalandi larvae under constant and varying temperatures

This study tested the effects of constant and varying temperatures on newly hatched yellowtail kingfish Seriola lalandi larvae in two experiments. In Experiment I, four constant temperatures (21, 23, 25, and 27 °C) were tested under fed or unfed conditions with the fish age from the day of hatch to 24 days post hatch (DPH). Temperatures at 25 and 27 °C reduced the time of fish to reach irreversible starvation, but did not affect the percentage of fish that were able to ingest food. Fish survivals at 21 and 23 °C were significantly higher than those at 25 °C by 24 DPH, but all fish died at 27 °C by 24 DPH in the treatment with food. In Experiment II, three constant temperatures (21, 23, and 25 °C) and two varying temperatures (21–23 and 21–25 °C) were compared using fish from hatch to 28 DPH. On 4 DPH, fish ingested more rotifers, but from 6 to 9 DPH, fish ingested fewer rotifers at 25 °C than at other temperatures. On 19 and 23 DPH, fish ingested more Artemia at 25 °C than at other temperatures. At 25 °C, fish selected for Artemia nauplii earlier than at other temperatures. Fish length and survival between constant temperatures (21 and 23 °C) were not significantly different, but fish survival at the constant 21 °C or at the 21–25 °C varying temperature was significantly higher than that at the constant 23 °C or at the 21–23 °C varying temperature. This study indicates that within the range of temperature tested, the optimal temperature for the first feeding larvae is 21–23 °C after hatch and mortality is likely to occur at ≥25 °C in the first 10 DPH, but fish grew faster at 25 °C after they adapted to the increasing temperature.     

Effect of temperature and salinity on sex inversion in Asian Seabass (Lates calcarifer): relationship with plasma sex steroids concentration and aromatase activity of gonad and brain

Asian Seabass which shows precocious sex inversion in cultured environment is a major impediment to maintain a proper broodstocks. Seabass grown commercially in freshwater were transported to the research facility and held in freshwater at 29°C for 4 weeks and acclimatized to the experimental conditions. Fish were daily fed with a commercial pellet (50% protein, 18 MJ kg^?1) to satiety. Blood, brain and gonad collected before and at the end of the experiment were analysed for sex steroids level and aromatase activity. There was an increase in Plasma E₂ levels with temperature in fish at 34°C whereas no significant difference was observed at 24 and 29°C although the highest plasma T level was detected in fish at 34°C which had significantly lower level than at the beginning, except those held at 24°C in freshwater. Plasma 11‐KT was significantly greater in fish at 24°C compared with 29 or 34°C which had clear opposite to the E₂. Aromatase activity in brain was higher at 29°C than at either 24 or 34°C, whereas gonadal aromatase recorded highest at 34°C. These findings concluded that high temperature in culture facility induces sex inversion of Asian Seabass.     

Histological and enzymatic responses of Japanese flounder (Paralichthys olivaceus) and its hybrids (P. olivaceus ♀ × P. dentatus ♂) to chronic heat stress

This study investigated the effects of long-term heat exposure on Japanese flounder (Paralichthys olivaceus) and its hybrids (P. olivaceus ♀ × summer flounder Paralichthys dentatus ♂). From 24 ± 0.5 °C, temperature was increased by 1 ± 0.5 °C in a day and was kept at that temperature for 5 days before next rise. Cumulative survival rate (CSR), cumulative survival rate under different temperature (CSR-T), histological alteration, and related enzyme activities were investigated. In P. olivaceus, mass mortality occurred at 29 and 32 °C (the CSR-T dropped to 42.39 %), and serious gill damages appeared at 30 and 32 °C. Meanwhile, the activities of superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), and pyruvate kinase (PK) declined around 29 and 32 °C (except for CAT). In comparison with P. olivaceus, the CSR of the hybrids was higher, the gill kept a better structural integrity, and the activities of SOD, CAT, LZM, and PK showed tiny fluctuations. The results suggested that during the process of chronic heat stress, P. olivaceus seemed to be more sensitive to 29 and 32 °C, and the manifestations in survival, histology, and enzyme activity were generally consistent. For the hybrids, the comparatively insensitivity to high temperature might imply its better heat tolerance.     

Resistance of Cobia,Rachycentron canadum,Juveniles to Low Salinity,Low Temperature,and High Environmental Nitrite Concentrations

Abstract

Resistance of juvenile cobia, Rachycentron canadum, to low salinity, low temperature and high nitrite concentrations was examined under laboratory conditions. After acclimating juveniles to a salinity of 20 g/L (27.3°C), salinity was decreased by 2 g/L/day. The first fish died at a salinity of 8 g/L and 80% offish were dead within 24 hours of exposure to 2 g/L. Acclimation offish to 22.6°C (21 g/L salinity) followed by a temperature reduction of 0.53°C/day resulted in initial mortality at 12.9°C. The median-lethal temperature was 12.1°C and all fish were dead by the time the temperature reached 10.4°C. Fish exposed for 96 hours to nominal ? 32 mg/L nitrite-N survived. Results of this study indicate that cobia juveniles require a salinity and temperature of > 8.0 g/L and > 12.9°C, respectively, and that environmental nitrite should not be deleterious at concentrations normally found in aquaculture systems.     

Influences of feeding frequency of extruded pellet and moist pellet on growth and body composition of juvenile Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> in suboptimal water temperatures

This study was carried out to investigate the influences of feeding frequency of extruded pellet and moist pellet on growth and body composition of juvenile flounder (initial mean weight 6.3 g) in sub optimal water temperatures. A 2 (diets: extruded pellet and moist pellet)×2 (feeding frequencies: two and three times daily)×2 (water temperatures: 12 and 17°C) factorial design with three replications was used. After 60 days of feeding, the feeding frequency did not significantly affect growth performance of fish. Weight gain, daily feed intake, feed efficiency and protein efficiency ratio were significantly (P<0.05) higher for fish reared at the higher water temperature. At the same water temperature, weight gain, feed efficiency, and protein efficiency ratio were significantly (P<0.05) higher for fish fed the extruded pellet than moist pellet. The results of this study indicate that feeding frequency of two times daily is sufficient for optimal growth of juvenile flounder when reared in suboptimal water temperatures, and an increase in water temperature from 12 to 17°C improved growth and feed efficiency.     

Abnormalities in the juvenile stage of sea bass (Dicentrarchus labrax L.) reared at different temperatures: types, prevalence and effect on growth

Osteological malformations are always considered an important problem in intensive aquaculture. This work studies the effect of rearing temperature on malformations in sea bass, Dicentrarchus labrax. To this end, two batches of the species were subjected to the following incubation/cultivation temperatures: 15 °C/natural and 19/19 °C, from fertilization until 190 days after hatching. The different malformations were studied in 1643 juveniles at 190 days and classified by categories. The Chi-square statistic was calculated to verify the relationship between the presence of anomalies and the application of different temperatures. The percentage of anomalies observed in individuals reared at a high temperature (19/19 °C) was 66.44%. In both temperature systems, opercular malformations were those which caused a greater delay in growth. The results found indicated that temperature played a very important role in the development of deformations, which may be of interest from the viewpoint of aquaculture.     

Effect of temperature on growth performance of greater amberjack (SERIOLA DUMERILI Risso 1810) Juveniles

In order to successfully diversify Mediterranean aquaculture, it is necessary to determine optimum culture conditions of potential candidate species such as greater amberjack (Seriola dumerili). Among culture conditions, rearing temperature is a key factor for achieving optimum growth and maintaining fish welfare. However, little is known about the optimum culture conditions of greater amberjack (Seriola dumerili). Thus, the aim of this study was to determine the effect of three different rearing temperatures (17, 22 and 26°C) during 120 days on growth performance, body morphometry, biochemical composition, gut transit and liver morphology of greater amberjack (Seriola dumerili) juveniles. After 120 days of rearing, fish raised at 26°C showed higher (p < .05) body weight and specific growth rate than fish held at lower temperatures, as well as improved feed utilization, protein efficiency and nutrient retention percentages. Fish stomach emptying was faster (p < .05) in fish raised at 26°C than in fish held at 22°C and 17°C. Similar results were obtained for gut transit time, being gut emptying faster (p < .05) in fish reared at 26°C than in fish cultured at lower temperatures. Rearing temperature also induced changes in fish morphology which resulted in a higher (p < .05) caudal propulsion efficiency index for fish reared at 26°C. Based on these results, we conclude that greater amberjack fingerlings perform better at 26°C than at 22°C or 17°C.     

Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA

Howell PJ, Dunham JB, Sankovich PM. Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA.
Ecology of Freshwater Fish 2010: 19: 96–106. This article is a US Government work and is in the public domain in the USA Abstract – Understanding thermal habitat use by migratory fish has been limited by difficulties in matching fish locations with water temperatures. To describe spatial and temporal patterns of thermal habitat use by migratory adult bull trout, Salvelinus confluentus, that spawn in the Lostine River, Oregon, we employed a combination of archival temperature tags, radio tags, and thermographs. We also compared temperatures of the tagged fish to ambient water temperatures to determine if the fish were using thermal refuges. The timing and temperatures at which fish moved upstream from overwintering areas to spawning locations varied considerably among individuals. The annual maximum 7‐day average daily maximum (7DADM) temperatures of tagged fish were 16–18 °C and potentially as high as 21 °C. Maximum 7DADM ambient water temperatures within the range of tagged fish during summer were 18–25 °C. However, there was no evidence of the tagged fish using localized cold water refuges. Tagged fish appeared to spawn at 7DADM temperatures of 7–14 °C. Maximum 7DADM temperatures of tagged fish and ambient temperatures at the onset of the spawning period in late August were 11–18 °C. Water temperatures in most of the upper Lostine River used for spawning and rearing appear to be largely natural since there has been little development, whereas downstream reaches used by migratory bull trout are heavily diverted for irrigation. Although the population effects of these temperatures are unknown, summer temperatures and the higher temperatures observed for spawning fish appear to be at or above the upper range of suitability reported for the species.     

Haematological and oxidative stress responses in Piaractus mesopotamicus under temperature variations in water

In this study, the influence of temperature variation on the blood and oxidative stress parameters of pacu Piaractus mesopotamicus juveniles was evaluated. Fish were subjected to gradual changes of temperature, over 5 days, by 24°C until reaching to experimental temperatures 18, 21, 24 (control), 27 and 30°C. There were significant differences (p < .05) in glucose and lactate of blood in both the haematological relationships and oxidative stress parameters. Glucose levels increased at 30°C and decreased at 21°C. Lactate levels were highest at 18°C. While the haematocrit was higher at all altered temperatures, haemoglobin levels decreased at 21°C and increased at 30°C, causing alterations in haematimetric indices. In the liver, glutathione‐S‐transferase (GST) activity was reduced at 18°C while antioxidant capacity against peroxyl radicals (ACAP) was highest at 30°C. Thiobarbituric acid reactive substances (TBARS) increased at 18, 21 and 27°C. In the muscle, ACAP decreased at 27 and 30°C and TBARS increased at 30°C. The results indicate that the species shows sensitivity to temperature variations. Accordingly, we conclude that with short‐term temperature variations >3°C, it is possible to induce higher alterations in the observed parameters in pacu juveniles.     

Effects of culture conditions on larval growth and survival of stalked barnacles (Pollicipes pollicipes)

Pollicipes pollicipes (Crustacea: Scalpelliformes) is a highly prized food in Portugal and Spain and consequently a species of considerable interest to aquaculture. Surprisingly, however, larval culture conditions for this barnacle have not been optimized. This study investigated the effects of temperature, diet, photoperiod and salinity on the growth and survival of P. pollicipes larvae. Temperature had a significant effect on specific growth rate (2.6–5.9% total width per day, from 11 to 24°C), reducing mean development time to the cyprid from 25 days at 11 °C to 10 days at 24°C, although this was accompanied by a significant increase in mortality to over 90% above 22°C. Mid‐range temperatures (15–20°C) maximized total survival (19–31% respectively). Algal diets of Tetraselmis suecica, T. suecica/Skeletonema marinoi and S. marinoi/Isochrysis galbana did not affect specific growth rate significantly, but survival (on average 39% in 15 days) and the proportion of high‐quality healthy cyprids was significantly higher on the latter two diets (11–15% of initial number of larvae). Photoperiod did not significantly affect the survival, although specific growth rate was significantly higher at 24:0 and 16:8 L:D. Salinity (20–40 g L^?1 range) did not affect growth and survival significantly. The best growth and survival were accomplished using rearing temperatures of 15–20°C, daily feeding with T. suecica/S. marinoi or I. galbana/S. marinoi and a photoperiod of 24:0 L:D.     

Effects of water temperature on feeding and growth of juvenile marbled flounder <Emphasis Type="Italic">Pseudopleuronectes yokohamae</Emphasis> under laboratory conditions: evaluation by group- and individual-based methods

To determine the optimal temperature for juvenile (0 year old) marbled flounder Pseudopleuronectes yokohamae, juveniles of 40–54 mm standard length were reared at six temperature conditions in the range of 8–26 °C, using group- and individual-based methods. Growth of juveniles increased from 8 to 20 °C but decreased from 20 to 26 °C, irrespective of the rearing method used. Food intake was greatest at 20 and 24 °C compared with other temperatures, while feed conversion efficiency was greater at 20 °C than 24 °C in individual rearing. Individual rearing provided more information such as individual variations in growth and food consumption, suggesting the importance of individual-based experiments for exploring the optimal temperature for fish.     

Sex differentiation of summer flounder (Paralichthys dentates L.) raised at practical hatchery temperatures

Female summer flounder grow considerably faster than males, and rearing temperature has been shown to influence sex differentiation in related species. The present studies were conducted to examine sex differentiation of post‐metamorphic juveniles reared at temperatures conducive for commercial production. In experiments 1 and 2, offspring produced from crosses with meiogynogenetic, sex‐reversed males and normal females were raised at 14, 16 or 18°C for ≥300 days or 12°C for 30, 60 or 120 days and then transferred to a male‐determining temperature (21°C). In all cases, the fish developed predominantly as phenotypic males (≥74%). In a third experiment, offspring produced from crosses with normal males and females were reared at 15, 17 and 19°C for 111, 227 and 278 days and then transferred to 21°C. Most fish (≥92.1%) developed as phenotypic males irrespective of rearing temperature or length of exposure. Several hypotheses are proposed for these findings and further research is necessary to understand the sex‐determining mechanisms in this species before the economic advantages associated with sexually dimorphic growth can be realized.     

Interactions of temperature,size and photoperiod on growth and smoltification of chinook salmon (Oncorhynchus tshawytscha)

Underyearling fall chinook salmon (Oncorhynchus tshawytscha) were reared at two temperatures (9 and 15°C) and three photoperiods simulating winter (WIN), spring—summer (SS), and natural (NAT) conditions. The two artificial photoperiods were adjusted according to fish size so that an equinoctial photoperiod was synchronized with a hypothesized optimum size range for smolting (8–14 cm fork length). Fish exposed to a winter (WIN) photoperiod had the slowest growth rate. Fish under the SS photoperiod at both temperatures and under the WIN photoperiod at 9°C displayed hypoosmoregulatory capability near the equinoctial daylength. Thyroxine concentrations in fish reared under a natural photoperiod remained at basal levels during the period of early saltwater adaptiveness and throughout the remainder of the experiment. Thyroxine titers showed significant increases under all experimental photoperiod—temperature combinations near the equinoctial daylength with the exception of the 15°C/SS treatment.     

Performance of Advanced Juvenile Cobia,Rachycentron canadum,Reared Under Different Thermal Regimes: Evidence for Compensatory Growth and a Method for Cold Banking

ABSTRACT

Two trials were undertaken to examine the growth response of juvenile cobia, Rachycentron canadum, at varying temperatures. The initial trial was conducted to determine the effect of various temperatures (18, 23, and 29°C) on weight gain and feed efficiency. The second trial investigated the effect of elevating water temperature in which fish maintained at 18°C and 23°C to a temperature close to their optimum (29°C). The latter study was undertaken in order to determine the effect of thermal shifts upon subsequent growth response of the species. Such information will assist commercial producers in developing various culture guidelines. As anticipated, differences (P < 0.01) in weight gain were recorded among all treatments, although remarkably, feed efficiency did not differ for cobia held at 23°C and 29°C. Following thermal shift, cobia subjected to the largest temperature change (18–29°C) illustrated an immediate growth response, but specific growth rates (SGR) did not exceed that of cobia held at 29°C for the duration of the trial. Nevertheless, when SGR were examined using fish of similar size (i.e., derived from different time points during the study) evidence for growth compensation was obtained. This study illustrates that cobia can be held at reduced temperatures, without detrimental impact on future performance, as a means of maintaining animals at smaller size for production and experimental purposes: “Cold banking.”     

Effect of temperature on the development, growth, survival and settlement of green mussel Perna viridis (Linnaeus, 1758)

The effect of temperature on the development, growth, survival and settlement of Perna viridis was studied under controlled conditions to provide information needed for the development of commercial hatchery technology for green mussel P. viridis. Total mortality of the larvae occurred after 24 h at temperatures of 33°C and 35°C. At 24°C, larvae took longer to settle than at temperatures of 27°C, 29°C and 31°C. For optimum larval development (8–13 h), growth (17.2±0.84 μm day^–1) and survival (55.2±0.84%), a hatchery rearing temperature of 31°C is required. For settlement no significant difference was seen between the percentage settlement at 29°C (49.3±3.34%) and 31°C (45.8±1.76%). However, the process of settlement began and ended earlier at 29°C (from 15 to 18 days) than at 31°C (from 18 to 20 days). Thus for larval settlement a temperature of 29°C is recommended.