Ammodytes Personatus Research Articles

The Effects of Alkaline Treatment and Potato-Starch Content on the Quality of Fish Meat Paste Products Prepared from Pacific Sandlance Ammodytes personatus Girard

This study investigated the effects of the number of washes and alkaline treatments (NaHCO 3 concentrations) and the concentration of potato starch on the quality of fish meat paste products prepared from sand lance Ammodytes personatus Girard. We found significantly ( P<0.05) higher ratings for the all textural parameters (hardness, brittleness, elasticity, and cohesiveness) of the sandlance meat paste products (SLMPPs) that were washed three times with a 0.5% NaHCO 3 concentration. We determined that an 8% concentration of potato starch leads to the best textural properties in SLMPPs. As the amount of potato starch was increased, the redness values of SLMPPs decreased significantly ( P<0.05), but the differences in the sensory evaluation parameters (texture, flavor, taste, and overall acceptability) between the SLMPPs were not significant.

Fine structures and functional characteristics of the gamete of the Japanese sand lance, Ammodytes personatus

Fine structures and functional characteristics of the gamete of the Japanese sand lance, Ammodytes personatus

Seasonal and spatial variations in prey utilization and condition of a piscivorous flatfish Paralichthys olivaceus

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 11:279-288 (2011) - DOI: https://doi.org/10.3354/ab00319 Seasonal and spatial variations in prey utilization and condition of a piscivorous flatfish Paralichthys olivaceus Takeshi Tomiyama1,3,*, Yutaka Kurita2 1Fukushima Prefectural Fisheries Experimental Station, Iwaki, Fukushima 970-0316, Japan 2Tohoku National Fisheries Research Institute, Shiogama, Miyagi 985-0001, Japan 3Present address: Soma Branch, Fukushima Prefectural Fisheries Experimental Station, Soma 976-0022, Japan *Email: tomiyama_takeshi_01@pref.fukushima.jp ABSTRACT: We investigated the diet and somatic condition of 5129 individual Japanese flounder Paralichthys olivaceus, 20 to 92 cm in total length, in the Joban area along the Pacific coast of Japan (36°40’N to 38°00’N) from 2001 to 2007. Japanese flounder with food in their stomachs (1668 individuals) consumed chiefly fishes (92% of stomach contents by weight). Predominant prey species were Japanese anchovy Engraulis japonica (54% of fishes by weight) and Japanese sandlance Ammodytes personatus (22%). Japanese anchovy were consumed by Japanese flounder year round except in March and April, when the anchovy migrate from the Joban area. In March and April, Japanese flounder frequently consumed Japanese sandlance, but only in the northern part of the Joban area (37°20’N to 38°00’N); Japanese flounder did not feed on this species and had less content in their stomachs in the southern area (36°40’N to 37°20’N), where the sandlance is absent. Somatic and hepatosomatic conditions of Japanese flounder in the northern area were better than those in the southern area in March and April, suggesting that such spatial and seasonal heterogeneities in prey availability affect the nutritional status of predators. KEY WORDS: Spatio-temporal variability · Prey availability · Body condition · Piscivory · Flounder · Generalized linear mixed models Full text in pdf format PreviousNextCite this article as: Tomiyama T, Kurita Y (2011) Seasonal and spatial variations in prey utilization and condition of a piscivorous flatfish Paralichthys olivaceus. Aquat Biol 11:279-288. https://doi.org/10.3354/ab00319 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 11, No. 3. Online publication date: February 23, 2011 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2011 Inter-Research.

Molecular identification of Ammodytes (PISCES, Ammodytidae) larvae, with ontogenetic evidence on separating populations

A total of ten larval Ammodytes were collected from the Yellow (5 specimens) and Bering Seas (5), and a 638 base pair sequence from their mitochondrial DNA COI genes was analyzed for species identification. Sequences were compared with those of adult Ammodytes personatus from the East (4), the Yellow (2) and the East China Seas (2), and Japan (3). Average genetic distance was 0.064 between the Yellow Sea larvae and the Bering Sea larvae, but was 0.0043 between the Yellow Sea larvae and all the adult A. personatus except two individuals from the East Sea. NJ-tree showed that five Yellow Sea larvae were closely clustered with adult A. personatus, except for two individuals. The five Bering Sea larvae were located distantly from adult A. personatus, and are thought to be A. hexapterus. We found morphological differences among two populations of A. personatus larvae and A. hexapterus larvae in morphometric characters and pigmentation. Our results indicated that the East Sea population of A. personatus is closer to A. hexapterus than to the Yellow Sea population of A. personatus, suggesting the East Sea population may be part of separate species.

The influence of particle size of dietary prey on food consumption and ecological conversion efficiency of young-of-the-year sand lance, Ammodytes personatus

Abstract The Eggers model was used to study the influence of two particle sizes of dietary prey on food consumption and ecological conversion efficiency of young-of-the-year sand lance, Ammodytes personatus, in continuous flow-through seawater in 2.5-m3 tanks in the laboratory. The sand lances (average body weight 0.85 ± 0.21 g) were fed larval (average body length 0.56 ± 0.08 mm) or adult (average body length 10.12 ± 1.61 mm) Artemia salina. The gastric evacuation rate of the fish feeding on larval Artemia was 0.214, higher than that of those feeding on adult Artemia (0.189). The daily food consumption of the fish feeding on larval Artemia was 60.14 kJ/100 g in terms of energy content, higher than that of the fish feeding on adult Artemia (51.69 kJ/100 g), but the daily growth rate of fish feeding on larval Artemia was 14.86 kJ/100 g, significantly lower than that of the fish feeding on adult Artemia (19.50 kJ/100 g), indicating that less energy was used for growth when the food particles were smaller. Slow growth of sand lances preying on larval Artemia was probably due to the high energy consumption during predation, consistent with the basic suppositions of optimal foraging theory.

Seasonal and inter-annual oceanographic changes induce diet switching in a piscivorous seabird

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 393:273-284 (2009) - DOI: https://doi.org/10.3354/meps08192 Seasonal and inter-annual oceanographic changes induce diet switching in a piscivorous seabird Motohiro Ito1,*, Hiroshi Minami2, Yuzan Tanaka1, Yutaka Watanuki1 1Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido, 041-8611, Japan 2National Research Institute of Far Seas Fisheries, 5-7-1 Shimizu, Shizuoka, 424-8633, Japan *Email: m-ito@fish.hokudai.ac.jp ABSTRACT: The structure of a marine food web can change quickly within seasons as well as inter-annually in response to physical oceanographic changes. In this study, we examined the relationship between temporal changes in the marine ecosystem of northern Hokkaido, Japan, and diets of rhinoceros auklets Cerorhinca monocerata breeding in this region. To obtain an integrated measure of changes in diet composition on short (days) and inter-annual (2004 and 2005) time scales, we used a 2-pronged approach. We examined (1) the diets of adults using stomach contents and stable isotope signatures in tissues, and (2) chick diets using the composition of bill-loads delivered to chicks. During the incubation period, the diet of adults comprised euphausiids (Thysanoessa longipes and T. inermis). During the chick-rearing period, the diet of adults was age 0 Japanese sandlance Ammodytes personatus and age 0 Japan Sea greenling Pleurogrammus azonus in the early period, but switched quickly (<10 d) to warm-water-preferring Japanese anchovy Engraulis japonicus when the warm Tsushima Current intruded into their foraging range. Adult blood plasma stable isotope ratios reflected these seasonal changes in stomach content. Diets did not differ between age categories. Furthermore, the timing of diet switching to anchovy differed inter-annually, and was about 10 d later in 2005 than 2004, reflecting a difference in the timing of the intrusion of warm water. We conclude that rhinoceros auklets respond sensitively to current-related rapid marine food web changes. KEY WORDS: Prey switching · Stable isotope signatures · Rhinoceros auklets · Anchovy · Tsushima Current Full text in pdf format PreviousNextCite this article as: Ito M, Minami H, Tanaka Y, Watanuki Y (2009) Seasonal and inter-annual oceanographic changes induce diet switching in a piscivorous seabird. Mar Ecol Prog Ser 393:273-284. https://doi.org/10.3354/meps08192 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 393. Online publication date: October 30, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

Isolation and characterization of eleven polymorphic microsatellite markers of sand lance (Ammodytes personatus)

Eleven polymorphic microsatellite markers were developed to delineate population structure of Ammodytes personatus. These markers had between 8 and 27 alleles. Expected heterozygosity ranged from 0.818 to 0.965, whereas the observed heterozygosity ranged from 0.441 to 0.886. Five of the eleven markers conformed to Hardy-Weinberg equilibrium. We believe the markers will be useful for genetic diversity study of A. personatus.

Reproductive potential and recruitment of sand lance Ammodytes personatus in Ise Bay, central Japan

Regular samplings of the Japanese sand lance Ammodytes personatus were carried out between 1991 and 2003 in Ise Bay in central Japan to estimate the number of adults, egg production and the number of recruits. The estimated minimum and maximum number of adults was 0.48 billion and 37.64 billion (78.4-fold variation). Age-one adults dominated in each year, and they comprised more than 80% of the total population in ten years out of the twelve years of observations. The total egg production ranged from 0.5 to 22.2 trillion (44.4-fold variation), and the total number of recruits ranged from 3.36 to 102.83 billion (30.6-fold variation). These interannual variations were both smaller than the interannual variations in the number of adults. As the total number of adults increased, the total egg production gradually became asymptotic at the saturation level, and the egg production per adult female decreased. In addition, the number of recruits per egg decreased as the total number of adults increased. It was suggested that both egg production and the initial process of mortality before recruitment exhibit density dependency.

Application of a generalized additive model (GAM) to reveal relationships between environmental factors and distributions of pelagic fish and krill: a case study in Sendai Bay, Japan

Abstract Murase, H., Nagashima, H., Yonezaki, S., Matsukura, R., and Kitakado, T. 2009. Application of a generalized additive model (GAM) to reveal relationships between environmental factors and distributions of pelagic fish and krill: a case study in Sendai Bay, Japan. – ICES Journal of Marine Science, 66: 1417–1424. A generalized additive model (GAM) was applied to fishery-survey data to reveal the influences of environmental factors on the distribution patterns of Japanese anchovy (Engraulis japonicus), sand lance (Ammodytes personatus), and krill (Euphausia pacifica). Echosounder and physical-oceanographic data were collected in Sendai Bay, Japan, in spring 2005. A hierarchical model was used with two spatial strata: (i) presence and absence of each species; and (ii) biomass density of each species, given its presence; and six environmental covariates (surface water temperature, salinity, and chlorophyll, and near-seabed water temperature, salinity, and depth). The results indicate non-linear responses of the two indices to the environmental covariates. In addition, the biomasses estimated by the GAMs were comparable with estimates based on conventional, stratified-random sampling for each species. GAMs are very useful for (i) investigating the effects of environmental factors on the distributions of biological organisms, and (ii) predicting the distributions of animal densities in unsurveyed areas.

Density and sound-speed contrasts, and target strength of Japanese sandeel Ammodytes personatus

Sound-speed and density contrasts (h and g, respectively), important acoustic material properties, of Japanese sandeel Ammodytes personatus were measured to estimate theoretical target strength (TS). The measured sound-speed contrast of adult fish varied between 1.016 and 1.023 (mean 1.020), and showed temperature dependence. The measured density contrast differed significantly between juvenile and adult. The density contrast of juvenile varied between 1.017 and 1.024 (1.021), and that of adult varied between 1.026 and 1.038 (1.032). Using these results, TS at 38 and 120 kHz in the fishing season were estimated by an empirical sound scattering model. TS of an individual fish varied significantly with change of tilt angle. TS of near-dorsal aspect (TSmax) and tilt-averaged TS (TSave) differed by up to 7 dB. At both frequencies, two different TSave−length relationships (TSave = a log L + b) were obtained for adult and juvenile. The coefficients of log L of adult were close to 20, suggesting that backscattering strength was proportional to square of body length. These values were larger in juvenile (34.0 at 120 kHz, 56.5 at 38 kHz), suggesting that backscattering strength varied drastically with the cube or fifth power of body length.

Geographic variations in Pacific sand eels Ammodytes personatus (Ammodytidae) from Korea and Japan using multivariate morphometric analysis

Multivariate methods were used to compare meristic and morphometric characters of Ammodytes personatus from four populations in Korea (3) and Japan (1). ANCOVA showed the slopes of head length (Japan > East > South > West) and body depth (South > Japan > East > West) relative to total length to differ significantly among populations. Vertebrae and fin rays’ numbers differed significantly among populations, the former ranging between 64 and 67 (mode = 65, 66) in the East population, 62–67 (63, 64) in the West population and 62–64 (62, 63) in the South population in Korea. PCA and CDA, based on 14 morphometric characters, showed that scores plotted on axes 1-2 and 2-3 separated the three Korean populations but overlapped between the South and Japanese populations. These results suggest that the Korean A. personatus may comprise at least two populations.

한국 연안산 어류의 미네랄 함량 및 영양평가

To measure the mineral content of fishes, we collected 177 individuals from 53 fish species from the east (Pohang), west (Gunsan), and south (Tongyeong) coasts of Korea. The mean content of the macro mineral in a 100 g sample taken from the edible portion of each fish was (in descending order): P(207.4 mg), K(169.7 mg), Na(101.6 mg), Ca(44.4 mg), and Mg(30.4 mg). In comparison, the mean content of micro mineral in the fishes was (in descending order): Zn (<TEX>$8.98{\mu}g/g$</TEX>), Fe (<TEX>$5.03{\mu}g/g$</TEX>), Cu (<TEX>$0.76{\mu}g/g$</TEX>), Mn (<TEX>$0.43{\mu}g/g$</TEX>), and Ni (<TEX>$0.08{\mu}g/g$</TEX>). We could not observe clear regional variation in the mineral content of fish species. With regard to minerals considered essential for humans, the amount of Ca per sample (100 g) was the highest in the Scyliorhinus torazame (465.4 mg), and than followed by Ammodytes personatus (338.0 mg), Dasyatis akajei (267.4 mg), Raja kenojei (248.1 mg), Conger myriaster (174.1 mg), Clupanodon punctatus (86.8 mg), Muraenesox cinereus (81.2 mg), and Engraulis japonica (70.4 mg). The daily average intake of the mineral through the fishes consisted of P (100.6 mg), K (82.3 mg), Na (49.3 mg), Mg (14.8 mg), Zn (0.44 mg), Fe (0.24 mg), Cu (0.04 mg) and Mn (0.02 mg). The respective intakes of macro mineral (P, Mg, Na, Ca, K) from the fishes were about 14.4, 4.2, 3.3, 3.1 and 1.8% of the dietary reference intakes for Koreans (KDRIs) set by the Korean Nutrition Society. In comparison, the respective intakes of micro mineral (Cu, Zn, Fe, Mn) from the fishes were about 4.6, 4.4, 2.4, and 0.6% of the KDRIs.

Dietary utility of enzyme-treated fish meal for juvenile Pacific bluefin tuna Thunnus orientalis

In order to develop an artificial diet, the dietary utility of enzyme-treated fish meal was investigated for juvenile Pacific bluefin tuna Thunnus orientalis (PBT). Diets containing each 63% of Chilean fish meal (FM), enzyme-treated chilean fish meal (EC) and enzyme-treated Peruvian fish meal (EP), with 10% bonito oil and raw sand lance Ammodytes personatus (SL) were fed to juvenile tuna six times per day for one week. In a different trial, diets EC and SL were fed to tuna six times per day for 2 weeks. Only diet EC sustained similar growth or caused lower survival and higher feed efficiency, hepato- and enterosomatic indices and final carcass lipid content as compared to those of SL. Diets FM and EP led to lower specific growth rate (SGR) but similar feed efficiency, survival and hepatosomatic index, yet higher enterosomatic index. Moreover, PBT fed diet EC for 2 weeks led to similar growth performance but higher final carcass and hepatic lipid contents, and plasma cholesterol and phospholipid levels than those fed SL. Carcass fatty acid composition of diet EC group had lower 20∶5 n-3 and 22∶6 n-3 levels than the SL group. These results revealed that EC, as a suitable dietary protein source, could sustain growth of PBT, while dietary bonito oil led to higher carcass lipid but lower accumulation of n-3 highly unsaturated fatty acids.

Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

Resource allocation in fledglings of the rhinoceros auklet under different feeding conditions: an experiment manipulating meal size and frequency

By manipulating meal size and frequency in an alcid, the rhinoceros auklet (Cerorhinca monocerata (Pallas, 1811)), we examined two hypotheses: (1) poorly fed chicks allocate resources preferentially to developing organs essential for fledging, and (2) intermittently fed chicks deposit more lipids than regularly fed ones. Chicks were fed normal (NORMAL; 40–80 g, mean meal mass in a normal year), small (LOW; 26–54 g, half of NORMAL), or large (HIGH; 80–160 g, twice as much as NORMAL) amounts of sandlance (Ammodytes personatus Girard, 1856) every day or the large meal (80–160 g) every 2 days (INTERMITTENT). Chicks fed more food grew faster. The HIGH group had the greatest fledging mass and shortest fledging period. The wingspan and brain mass of fledglings did not differ among groups. The heart, liver, and breast muscle at fledging were 15%–25% smaller in the LOW group than in the NORMAL group but did not differ between the NORMAL and HIGH groups. The total lipid was 43% greater in the HIGH group than in the NORMAL group, and that of the LOW group was 38% smaller. The INTERMITTENT group had a similar lipid mass to the NORMAL group. Chicks feeding on small meals seemed to maintain the growth of organs essential for fledging, while chicks feeding on large meals seemed to deposit a surplus as lipid rather than allocate more to the development of organs.

Morphology, stomach contents and growth of the endangered salmonid, Sakhalin taimen Hucho perryi, captured in the Sea of Okhotsk, northern Japan: evidence of an anadromous form

We describe a total of 25 anadromous Sakhalin taimen Hucho perryi collected on the coast of Sarufutsu, northern Hokkaido, Japan in June 1997 and 1999. We examined morphology, stomach contents and growth of three anadromous taimen (one male and two females) in detail, which were preserved in good condition. The three taimen were aged and one female still had some eggs retained in her abdomen. The stomach contents of the three taimen consisted of sand lance Ammodytes personatus Girard and sculpin Triglops sp. On the basis of scale analyses, the growth rate of the three taimen was estimated by using the back-calculation method, and the highest rates were observed at young ages. Guanine pigmentation was present at the base of the caudal fin of each taimen and is considered as a potential morphological trait to differentiate anadromous from fluvial specimens. Another anadromous taimen, of which some individuals had reared for more than 3 years in seawater are also reported. For the conservation of this rare and endangered species, their migration route between rivers and sea should be protected

Anesthesia, fasting tolerance, and nutrient requirement of juvenile northern bluefin tuna

The present study aimed to investigate a suitable anesthesia protocol for nutritional studies, fasting tolerance, and nutrient requirements for maintenance in juvenile northern bluefin tuna Thunnus orientalis weighing 0.8–0.9 g. The fish grew in a mass seedling production under completely controlled aquaculture. The solution of 0.2 mL 2-phenoxyethanol/L prepared by filtered seawater has been notably estimated as a anesthesia protocol for the juvenile, due to a shorter mean time necessary for anesthesia and recovery and higher survival rate at 24 h after recovery. All other anesthetics, 0.1 and 0.3 mL 2-phenoxyethanol/L, 0.05, 0.1 and 0.2 mL 4-allyl-2-methoxyphenol/L, and cool water temperature shocks at 16.8, 12.6 and 10.4°C, were inferior. In a 5-day tolerance test, the juvenile was fed sand lance Ammodytes personatus through the rearing period or fasted for 2, 3, 4 and 5 consecutive days. Survival rates were about 80 or 60, 50, 10 and 0%, respectively. From the relationships between days fasting and energetic and nutritional retentions, juvenile tuna require about 142.7 kJ, 5.46 g protein and 0.44 g fat/kg body weight a day for maintenance, indicating remarkably higher requirements than other aquaculture fish.

Audiogram measurement based on the auditory brainstem response for juvenile Japanese sand lance Ammodytes personatus

In this study, the auditory thresholds for juvenile Japanese sand lance Ammodytes personatus were measured based on its auditory brainstem response (ABR). The amplitude of the ABR waveforms to a sound stimulus were larger than that of the electric background noise caused by general brainwaves and myogenic signals after the averaging procedure. Japanese sand lance responded to low frequency sounds between 128 Hz and 512 Hz with a sound pressure level of 115–125 dB. As the test frequency decreased, so did the auditory threshold level, and the level was about 116 dB at 128 Hz and 181 Hz. These results indicate that Japanese sand lance can detect low frequency sound but are less sensitive than other fish species. These high thresholds are probably caused by the lack of a swim bladder.

Improved survival and growth in Octopus vulgaris paralarvae by feeding large type Artemia and Pacific sandeel, Ammodytes personatus: Improved survival and growth of common octopus paralarvae

Rearing experiments of common octopus, Octopus vulgaris, paralarvae were carried out during the first month of life by feeding with large type Artemia or small type Artemia supplemented with defrozen flakes of Pacific sandeel, Ammodytes personatus. Two experiments, based on different scale tanks of four 500 l circular tanks and two 4000 l rectangular tanks, were carried out in June to July 2003 to investigate the survival, growth and HUFA composition of the paralarvae and food organisms. The survival rate of paralarvae was significantly higher in the large type Artemia supplied groups (47.4% and 45.9%) than the small type Artemia supplied groups (8.8% and 2.7%). Similarly, the mean wet weight was 26.2 and 37.3 mg for the 25 and 32 day old paralarvae in the large type Artemia groups while 20.3 and 18.2 mg in the small type Artemia groups. The survival rate and growth of the large type Artemia groups were higher than the small type Artemia groups and the values given in the previous studies. Feeding large type Artemia and sandeel flakes was concluded as effective for improving survival and growth of the common octopus paralarvae. The DHA/EPA ratio in the 32 day old paralarvae of both Artemia supplied groups was equal 1.5, similar to that of hatchlings and wild subadults. Supplementing sandeel flakes improved the DHA/EPA ratio of the paralarvae, since both types of Artemia contained only minimal DHA. However, the reason(s) for the improved survival rate and growth between the large type Artemia supplied group and small type Artemia supplied group still remain to be solved.

Assimilation efficiency of Rhinoceros Auklet ( Cerorhinca monocerata) chicks fed Japanese anchovy ( Engraulis japonicus) and Japanese sand lance ( Ammodytes personatus)

We investigated the assimilation efficiency (AE) of a piscivorous alcid, Rhinoceros Auklet ( Cerorhinca monocerata), chicks when fed Japanese anchovy ( Engraulis japonicus) and Japanese sand lance ( Ammodytes personatus), which are their main prey species. The assimilation efficiency corrected for nitrogen retention (NR) of the chicks fed sand lance (81.6%) was significantly higher than those fed anchovy (78.0%). The values of assimilation efficiencies for both fish species are similar to those of fish-fed seabird adults and fledglings.