Dietary selectivity in the field and food preferences in the laboratory for two herbivorous fishes (Cebidichthys violaceus and Xiphister mucosus) from a temperate intertidal zone

Diets and food selectivity of two stichaeid fishes (Cebidichthys violaceus and Xiphister mucosus) from the rocky intertidal zone of the central California coast (USA) were studied at each season of the year by gut content analysis and abundance measurements of potential macrophyte food items. Both fishes, after reaching a standard length of about 44 mm, were almost exclusively herbivorous. The bulk of the diet consisted of 8 to 10 species of chlorophytes and rhodophytes. These main dietary components were chiefly annual seaweeds with high surfaceto-weight ratios (sheetlike forms or small, highly branched forms). Perennial seaweeds were eaten in relatively large amounts only during the winter. Macrophytes eaten in only trace amounts included about 20 species of chlorophytes, chrysophytes, phaeophytes, rhodophytes and a spermatophyte. The small amount of animal material in the diet (never more than 2% by weight) could well have been ingested incidentally while the fishes were feeding on seaweeds. Food preference tests with up to 19 macrophyte species in the laboratory revealed that both fishes chose to eat three annual rhodophytes (Smithora naiadum, Porphyra perforata and Microcladia coulteri) in preference to Ulva lobata, an annual chlorophyte that was more abundant in the diets of field-caught specimens.     

Comparison of herbivory in the closely-related marine fish genera Girella and Kyphosus

  Specimens of the nominally herbivorous, closely-related, fish genera Girella and Kyphosus were collected from Australian waters in 1994 and 1995. The diet of three Girella species (G. cyanea, G. elevata, and G. tricuspidata) consisted mainly of chlorophytes and rhodophytes, with an animal component of␣15.9 ± 4.2% in G. tricuspidata. The diet of four species of Kyphosus (K. bigibbus, K. cinerascens, K. sydneyanus, and K. vaigiensis) included phaeophytes, chlorophytes and rhodophytes, and almost no animal material. Concentration of total short-chain fatty acids in the posterior intestine was <11.4 mM in the Girella spp. and >39.2 mM in the Kyphosus spp. These results suggest that microbial fermentation plays a role in algal digestion in Kyphosus spp., but not in Girella spp. Girellids and kyphosids appear to function quite differently as herbivores. Girellids should be considered as omnivores that complement readily-available energy from algae with protein from invertebrates. Kyphosids appear to be strict herbivores that can derive adequate nutrition from algae poor in easily assimilable energy, through microbial fermentation in the hindgut. Received: 8 July 1996 / Accepted: 2 August 1996     

Effects of experimental feeding and starvation on the proximate composition of the European bass Dicentrarchus labrax

Juvenile bass, Dicentrarchus labrax (L.), fed ad libitum on trout pellets, the shore crab Carcinus maenas and filleted saithe, Gadus virens, did not differ significantly in proximate composition although the diets were absorbed with high efficiencies of 94 to 99% and differed greatly in composition. Compared with wild fish, the white muscle, dark muscle, liver and mesenteric fat bodies of laboratory-reared bass were lower in moisture and higher in lipid. Starvation caused a rapid initial decrease in carbohydrate and a progressive decline in lipid in all tissues, coupled with an increase in moisture and ash contents. The liver and fat body somatic indices also declined, indicating that these organs are the major lipid storage depots in bass, in contrast with the skeletal muscle which has this role in other active fishes such as salmonids and clupeids. Lipid and protein are inversely related to moisture content in whole specimens.     

A link between biologically imported particulate organic nutrients and the detritus food web in reef communities

Previous work with planktivorous fishes has shown that they import particulate organic and inorganic material to reefs in the form of fecal pellets, which, in part, are deposited in crevices on the reef where these fishes shelter during their inactive period. Since these feces do not accumulate in fish shelters, we predicted that some of the feces could be rapidly consumed by reef detritivores. We examined the attractiveness of fish feces to potential reef detritivores by placing traps baited with planktivorous fish feces, along with unbaited control traps, in crevices on rocky reefs at Santa Catalina Island, California, USA, between June 1982 and November 1983, and on coral reefs at St. Croix, U.S. Virgin Islands, during June 1983. Significantly more animals (the majority being crustaceans) were trapped in the baited traps compared to the unbaited controls on both reefs. There was also a significant association between the presence of trapped animals and fish feces at Santa Catalina Island (p = 0.009); this association was not quite as strong in St. Croix (p = 0.069). The consumption by shrimp of feces marked with carmine particles and, in turn, the predation on these shrimp by a reef fish demonstrates the links between this type of imported particulate organic and inorganic material and the food web of the reef community.Please address all correspondence and requests for reprints to Dr. Miller at California State University, Long Beach     

Concentration of lodine and bromine by plants in the seas of Japan and Okhotsk

Iodine and bromine content were measured in 24 species of red (Rhodophyta), brown (Phaeophyta) and green (Chlorophyta) seaweeds and 2 species of higher water plants (Embryophyta) from the Sea of Japan, as well as in 12 species of the abovecited taxa and 1 species of flowering plant from the Sea of Okhotsk. Iodine was determined by photometric extraction with brilliant green, and bromine by neutron activation of samples. Phaeophyta and Rhodophyta were richest in iodine and bromine content. Representatives of the order Ceramiales (Rhodophyta) had high iodine and bromine contents. Thus, iodine concentrations in Ptilota filicina, Campylaephora hypnaeoides and Myriogramme yezoensis, a new iodine concentrator discovered by us, amount to 0.42, 0.094 and 0.75%, respectively. Bromine content in representatives of the family Rhodomelaceae was 3.36 and 3.74% in Japan Sea and Okhotsk Sea Rhodomela larix, respectively. Polysiphonia japonica (Rhodomelaceae) is a newly discovered concentrator of bromine (3.20%). Many species of the order Laminariales (Phaeophyta) were characterized by high iodine contents: Laminaria japonica, L. cichoriodes, L. inclinatorhiza, Cymathaere japonica and Alaria marginata. The Br:I ratio for all the species except those that concentrated iodine, was more than 1. Seaweeds that grow at greater depths showed increased iodine and bromine contents. A tendency toward increased iodine content was observed in species growing further to the North. Iodine and bromine were accumulated selectively by various organs of Sargassum pallidum.     

Blooms of surf-zone diatoms along the coast of the Olympic Peninsula,Washington. X. Chemical composition of the surf diatom Chaetoceros armatum and its major herbivore,the Pacific razor clam Siliqua patula

The surf diatom Chaetoceros armatum T. West, collected from its natural habitat along the Washington coast (USA), had a large inorganic component in the form of a clay coat (consisting of clay minerals, illite and montmorillonite) surrounding the cell chains: 63% of the dry weight of the natural material collected in November was inorganic. The organic fraction was composed of 67.6% lipid, 29.7% protein, and 1.3% carbohydrate. Culture cells were likewise high in protein and lipid and low in carbohydrate. Traces of chitin found in field samples were probably a contaminant, since chitin was absent from cultured cells. This diatom species serves as a major food source throughout the year for the Pacific razor clam Siliqua patula Dixon, which inhabits these same beaches. Protein constituted 47% and lipid 42% of the dry weight of razor clam tissue. The fatty acid distribution in the diatom lipid resembled that previously reported for other diatom species; similarly, the fatty acid distribution of the clam lipid was similar to that previously reported for other bivalve molluscs. The clam fatty acids differed in chain length and degree of saturation from those extracted from its food source, indicating an active fatty acid metabolism in the clam.Contribution No. 995 from the Department of Oceanography, University of Washington, Seattle, Washington 98195, USA.     

A comparison of absorption and assimilation efficiencies between four species of shallow- and deep-living fishes

We captured two species of deep-sea zoarcids, Melanostigma pammelas and Lycodapus mandibularis, from Monterey Bay California and maintained them in the laboratory. One shallow-water zoarcid, Eucryphycus californicus, and an ecologically and morphologically similar stichaeid fish Xiphister atropurpureus were collected from intertidal and subtidal habitats in Monterey Bay. We investigated the absorption and assimilation efficiencies of these fishes to determine whether deep-sea species have evolved mechanisms to increase their efficiency of food use. Fishes were placed in experimental chambers and fed a known quantity of food. Ammonia excretion was measured and feces were collected daily. Both food and feces were analyzed for water, protein, lipid and ash to determine specific absorption efficiencies. Absorption ranged from 87.7 to 92.4% and assimilation efficiencies from 84.0 to 86.5%. Meal sizes from 0.5 to 4.0% of body weight did not affect the results. No significant differences were found between deep-sea and shallow-water species fed single meals or fed ad libitum for 10 days. This suggests that the selective pressure to maximize absorption and assimilation is universal and is not affected by the productivity of the habitat occupied. However, the relative size of the intestine in the deep-sea species was significantly smaller suggesting that they had a lower metabolic cost to maintain their digestive apparatus. It could not be concluded whether this was the result of pressure to conserve energy or rather the tendency of the shallow-living species to ingest more refractory material (i.e. sediment, algae).     

Temporal variation in protein, carbohydrate, and lipid concentrations in Paramuricea clavata (Anthozoa, Octocorallia): evidence for summer–autumn feeding constraints

Temporal variations in protein, carbohydrate, and lipid levels were studied in a passive suspension feeder, the gorgonian Paramuricea clavata. The samples were collected every month for mature and immature colonies over a three-year period (1997–2000). The relationship between biochemical composition and reproductive output was examined on the basis of the 1998 and 1999 data. In female and male P. clavata colonies, the tissue displayed differences in lipid concentrations only in winter–spring, due to the high lipid levels attained by female colonies in this period. Immature colonies showed significant differences in lipid concentration only with respect to mature females in spring. There were clear seasonal trends in the lipid and carbohydrate levels in P. clavata, with maximum values in winter–spring [male lipid 212±75 SD μg mg⁻¹ of organic matter (OM) and female lipid 274±103 SD μg mg⁻¹ of OM; male and female carbohydrate 68±14 SD μg mg⁻¹ of OM], coinciding with maximum food concentration/quality, and minimum values in summer–autumn (male and female lipid 155±57 SD μg mg⁻¹ of OM; male and female carbohydrate 56±14 SD μg mg⁻¹ of OM), coinciding with low food concentration/quality. The relationship between reproductive output and tissue concentrations of lipids, carbohydrates, and proteins was not straightforward, although there was an evident overlap of the lipid accumulation and the gonadal development. The results of this study show that protein, carbohydrate, and lipid levels may provide a record of episodes in the ecological cycle bearing on the trophic aspects of the target species. The results indicate that information on seasonal biochemical levels may explain benthopelagic coupling processes, provided factors such as natural diet, feeding rates, reproduction, and growth are well understood.     

Influence of season,ontogeny and tide on the diet of the temperate marine herbivorous fish Odax pullus (Odacidae)

The diet of the temperate marine herbivorous fish Odax pullus (Pisces: Odacidae) was examined using gut-content analysis followed by principal-component analysis and analysis of variance. Fish were collected near Leigh, on the northeast coast of New Zealand, from February 1983 to September 1984. The data were categorised by size of fish, season, and state of tide. A major ontogenetic shift in diet was observed. Juveniles fed on animal material (crustaceans and gastropods), epiphytic rhodophytes, and some phaeophyte material. Adults fed almost exclusively on two phaeophyte taxa, the laminarian Ecklonia radiata and the fucoid Carpophyllum spp. Dietary selection was evident at the level of particular plant components; the diet of larger fish in spring samples was dominated by fucoid reproductive receptacles. There was no direct evidence of a tidal influence on diet composition of O. pullus, although the relative proportions of E. radiata and Carpophyllum spp. ingested by adult fish appeared to vary with tidal state. The volume of gut contents varied seasonally for all size classes, although the timing of peak annual food intake varied among size classes. Tidal state did not influence the volume of the gut contents. The ontogenetic and seasonal trends evident in the diet of O. pullus appeared to be related to a number of factors including relative gut length, gonad development, ontogenetic changes in feeding anatomy and seasonal changes in algal composition.     

Gut characteristics and assimilation efficiencies in two species of herbivorous damselfishes (Pomacentridae: Stegastes dorsopunicans and S. planifrons)

The morphological and physiological mechanisms by which marine herbivores assimilate energy and nutrients from primary producers and transfer them to higher trophic levels of reef ecosystems are poorly understood. Two wide-ranging Caribbean fishes, the dusky damselfish, Stegastes dorsopunicans, and the threespot damselfish, S. planifrons, defend territories on patch reefs in the Archipelago de San Blas, Republic of Panama. We examined how relative intestine length and retention time influence digestion and absorption of energy and nutrients in these fishes. The dusky damselfish has a relative intestine length (RIL=intestine length/standard length) of 1.2 and a Zihler index {ZI=intestine length (mm)/10[mass(g)^1/3]} of 3.4. These values are significantly lower (P_RIL=P_ZI<0.0001) than those for the threespot damselfish (3.0 and 8.2, respectively). Both RIL and ZI for both species fall well below previously published values for other herbivorous pomacentrids, and may reflect their primary food resource at San Blas (diatoms). Energy-rich diatoms may be easier to digest than refractory macroalgae characteristic of diets of many herbivorous fishes (RIL range: 2-20). Despite differences in RIL and ZI between these two species, gut retention time is the same (P>0.05) for both dusky (6.6 h) and threespot damselfish (6.5 h). Thus, food travels the length of the threespot damselfish intestine ~2.5 times faster than it does in the dusky damselfish intestine. Levels of protein, carbohydrate, and lipid are significantly (0.003<P<0.030) higher in the feces of dusky damselfish than in the feces of threespot damselfish, when both species were fed a natural diet of benthic diatoms collected from damselfish territories. This indicates threespot damselfish have a greater nutrient-specific and total assimilation efficiency than do dusky damselfish. Furthermore, when fed an artificial pellet diet, protein absorption efficiency differed significantly (P=0.014) between species; threespot damselfish absorbed 98.3% of dietary protein, whereas dusky damselfish absorbed 96.4% of dietary protein.     

Nutritional quality of macrophytes eaten and not eaten by two temperatezone herbivorous fishes: A multivariate comparison

The mean annual chemical compositions (ash, lipid, carbohydrate, protein, nitrogen and carbon) of 23 species of macrophytes (22 seaweeds and 1 seagrass) from a rocky intertidal habitat on the central California coast were determined from December 1981 through December 1982. These data were used to test the hypothesis that the 13 red and green seaweeds eaten by the two principal herbivorous fishes (Cebidichthys violaceus andXiphister mucosus) at the site are higher in nutritional quality than the 9 red and brown seaweeds and the seagrass not consumed by these fishes. A MANOVA using the ash, lipid, carbohydrate and nitrogen data showed that the centroids of the dietary and nondietary species groups were significantly different. In a two-group discriminant analysis that followed, only two species were misclassified as members of the opposite group. Multigroup discriminant analysis of the 23 macrophytes resulted in some overlap among dietary and nondietary species. Species were discriminated on the first canonical axis by ash content and on the second and third axes by lipid and carbohydrate contents. Nitrogen contributed little to the overall discrimination of species in the analysis. The nondietary red algaCorallina vancouveriensis, with its high ash content and therefore relatively low nutritional quality, was clearly separated from all other species in the analysis. Brown algae were of higher nutritional quality, but are not eaten by the two fishes, possibly because these seaweeds produce indigestible carbohydrates and secondary compounds. However, the exclusion from the diets of several red algal species that were virtually indistinguishable from the dietary red algae remains unexplained.Contribution No. 64 from the Ocean Studies InstitutePlease address all correspondence and requests for reprints to Dr. Horn at Fullerton     

Characterization of in vivo absorption features of chlorophyte,phaeophyte and rhodophyte algal species

Despite the plentiful diversity of macroalgae in coastal environments, few studies have examined the in vivo absorption features of common marine macrophytes. Here we report on results of a survey of 12 central California common intertidal and subtidal taxa, representing Chlorophyta, Phaeophyta and Rhodophyta carried out in the summer of 1988. Computer-assisted analyses were used to obtain fourth-derivative spectra from in vivo absorption spectra determined at room temperature to obtain spectral diagnostics for the different algal divisions and to provide a means to determine whether spectral features could be used to identify stress responses among these plants. Among the Chlorophyta, characteristic maxima for chlorophylls a and b were resolved in all species examined, and a spectral component attributable to siphonaxanthin-like carotenoid(s) was observed in two Ulva species and the coenocytic alga Derbesia marina. Representatives of the Phaeophyta were characterized by similar maxima for chlorophyll a and c, and for fucoxanthin. Among the Rhodophyta, maxima for chlorophyll a, as well as B- and R-type phycoerythrin were resolved. Differences in in vivo absorption features were detected for two tidal populations of Porphyra perforata and Mastocarpus papillatus. High-tidal thalli absorb less green light in regions characterized by phycoerythrin, but have enhanced carotenoid absorption compared with lowtidal thalli. Resolution of spectra by fourth-derivative analysis revealed significant differences in phycoerythrin and carotenoid contents. The spectral changes observed appear to reflect environmental and possibly populational characteristics of these algae. The spectral analyses described here provide robust, non-invasive means to characterize subtle responses of macroalgae to environment in ways not possible previously. Additional merits of these fourth-derivative analyses for use in environmental studies are discussed.This contribution is dedicated to the memory of Professor L. R. Blinks, a pioneer in photosynthesis research and algal physiology     

Fatty acid composition of marine macroalgae from the Black Sea and Dardanelles

The fatty acid (FA) composition was determined in 14 species of marine macroalgae belonging to the Chlorophyta, Phaeophyta and Rhodophyta, which were collected from ?ile in the Black Sea and Kepez in the Dardanelles. Generally, polyunsaturated FAs and monounsaturated FAs were major components (50–77%). Total saturated FAs ranged from 22% to 50%, with 16?:?0 as the most abundant saturate (32–38%). Two samples of Cystoseira barbata collected from a different station had some differences from each other in their contents of 18?:?2n-6 and 18?:?3n-3 and in the 18?:?2n-6/20?:?4n-6 ratios. Green algal species had a significantly higher proportion of unsaturated FAs and a significantly lower proportion of saturated FAs than the red and brown algae. The amount of n-3 FAs was significantly higher in Ulva rigita, Chaetomorpha linum, Enteromorpha linza and Gracilaria verrucosa (8.88, 6.44, 5.31 and 5.24, respectively).     

Nitrogen content of food as an index of absorption efficiency in fishes

Gravimetric estimation of absorption efficiency in fishes is a time-consuming process and still subject to technical errors. Available marker methods require no quantitative recovery of feces, but their applicability is limited (e.g. chromic oxide method) or their reliability is questionable (e.g. Conover's ash ratio method). From over 100 values reported for about 50 fish species, it has been observed that nitrogen content of food holds a positive correlation to absorption efficiency; the relation is significantly (P<0.001) correlated (r=>0.9). Hence absorption efficiency (Ae) of fishes is predictable from the nitrogen content of food with less than 8% error, using the equation log Ae=1.3706+0.5807 log N.Dedicated to Professor O. Kinne on his 61st birthday, August 30, 1984     

High molecular weight algal substances in the sea

Phytoplankton exudates into culture media and extracts from littoral algae are shown to contain significant quantities of extracellular materials having molecular weights in excess of 50,000. A recent development in experimental fluid mechanics (the reduction of turbulent friction coefficients of flowing solutions by dissolved macromolecules) has been utilized as a specific test for high molecular weight compounds. Phytoplankton species in all major algal groups could be found which exude high molecular weight compounds into their culture media; the red alga Porphyridium cruentum typically produced friction reductions as high as 60%. Seaweed samples in the Chlorophyta, Phaeophyta, and Rhodophyta showed major changes in turbulent friction coefficient; in some cases the friction was less than 1/2 that of pure seawater. All samples of the genus Porphyra and Gigartina produced substantial friction changes. From these experiments it is concluded that algal exudates can be a prominent source of high molecular weight compounds in the sea.     

投饵养鱼对潘家口水库藻类生长影响的围隔试验研究

设置投饵、投饵单养花鲢（Aristichthisnobilis）、投饵单养鲤鱼（Cyprinuscarpio）、投饵混养花鲢和鲤鱼以及空白对照5个围隔及水库背景水体,研究投饵养鱼对潘家口水库浮游藻类生长和群落结构的影响。结果发现,试验期间水库水体和空白对照围隔中总藻平均密度分别为2.60×10^6L^-1和3.38×10^6L^-1,均以蓝藻和绿藻为主且基本保持稳定状态;投饵能有效促进藻类生长,只投饵围隔中总藻平均密度达到1.17×10^8L^-1,藻种组成向单一鱼腥藻（Anabaena）方向演替;养殖花鲢抑制藻的生长,参照只投饵围隔,抑制率接近80%,绿藻占据极大优势,其中栅藻（Scenedesmussp）、芒锥藻（Errerellabornhemiensisconr）和空星藻（Coelastrumsp）成为优势藻种;投饵养殖鲤鱼也能有效降低藻生物量,总藻平均密度为4.07×10^7L^-1,绿藻占总藻的比例由27%增加到95%,其中空星藻和小球藻（ChlorellavulgarisBeij）为优势藻种;投饵混养花鲢和鲤鱼围隔中总藻密度稍高于单养花鲢和鲤鱼围隔,为4.37×10^7L^-1,栅藻和鱼腥藻为优势藻种。     

Chemical composition of dietary species of marine unicellular algae and rotifers with emphasis on fatty acids

The lipid profiles of a few species of marine unicellular algae and yeast were studied with emphasis on fatty acids as part of a search for the nutritional value of plankton to the diet of marine fish larvae commonly used in marine hatcheries. The general proximate chemistry of rotifers was closely related to the proximate chemistry of the diet organism, exhibiting a higher content of protein and carbohydrate and a lower content of lipid. Major lipids in all algae, yeast and rotifers comprised mono-, di- and tri-glycerides and polar lipids. The algae Chaetoceros gracilis Schutt, Isochrysis galbana Parke and their respective algaefed rotifers exhibited higher amounts of neutral lipids, consisting mainly of cyclic and branched polyunsaturated components. Fatty acid composition of the algae was species-specific, with the highest ratio of polyethylenic to saturated and monoethylenic acid in I. galbana and Phaeodactylum tricornutum Bohlin, and the highest content (15%) of n-3 highly unsaturated fatty acids in Nannochloropsis salina and P. tricornutum. A closely mirrored distribution of the fatty acids, but with a lower amount of n-3 highly unsaturated fatty acids, was present in the respective algae-fed rotifers. Comparison of the fatty acid spectrum of Artemia sp. and Euterpina acutifrons grown in the laboratory on I. galbana with zooplankton samples of E. acutifrons and Oitona nana collected from the sea showed a higher concentration of docosahexaenoic acid (22:6 n-3) in the naturally collected sample. The results indicate that the efficacy of the food algae C. gracilis and I. galbana in increasing the survival of fish larvae in marine hatcheries is not obvious on the sole basis of fatty acid composition.     

Organic and caloric levels of fish feces relative to its consumption by coprophagous reef fishes

Levels of protein, lipid, carbohydrate, ash, and calcium in the rectal contents of a species representative of each of four trophic groups of coral reef fishes were determined. These levels and the estimated caloric levels were related to the degree to which the feces of each species were eaten by species of coprophagous fishes and to the potential nutritional value of their non-fecal foods. The potential nutritional value of feces (based on estimated caloric content), protein and lipid levels were positively correlated with the percentage of feces eaten by coprophagous fishes. Levels of calcium and ash were negatively correlated with the percentage eaten. Fecal carbohydrate level was not correlated with the degree of ingestion. Food values of these feces were at least equal to those of non-fecal foods (i.e. zooplankton, coral tissue, algae, etc.) of the coprophages. Feces produced by the coprophagous species had even lower potential food value.     

Effects of salinity on food intake,absorption and conversion in the rainbow trout Salmo gairdneri

In rainbow trout (Salmo gairdneri Richardson) which had been acclimatised to the experimental salinity and temperature, food intake was maximal in the intermediate salinities of 15.0 and 28.0%, less in fresh water and 7.5% and minimal, by a statistically significant margin, in 32.5%. There were marked day-to-day fluctuations in food intake. When salinity was abruptly increased by 7.5 or 13.0%, there were decreases in growth rate which were related to decreases in food intake. Recovery of food intake and growth rate to pre-increase levels was complete within 14 days. Absorption efficiency, in terms of total dry matter, total energy and total nitrogen, was negatively related to salinity. Total nitrogen was absorbed considerably more efficiently than either energy or dry matter. Conversion efficiency (K ₁ and K ₂) was estimated, also in terms of dry matter, energy and total nitrogen, in trout of the O+ and 1+ year groups weighing from 50 to 150 g. There was a tendency for conversion efficiency to decline with salinity, especially between 28.0 and 32.5%. Dry matter and energy conversion were significantly lower than nitrogen conversion efficiency.     

Fish-bone oil: Percent total body lipid and carbon-14 uptake following feeding of 1-14C-palmitic acid

Bones contain the majority of body lipid in some marine fish. In the sheepshead wrasse Pimelometopon pulchrum and the sablefish Anoplopoma fimbria, the bone lipid comprised 79 to 93% and 52 to 82% of the total body lipid, respectively. The senorita Oxyjulus california, another species of wrasse, has only 14% of its body lipid in bone. To determine whether dietary lipid is deposited quickly in the bone lipid, three species of fish were fed 1-¹⁴C-palmitic acid. Radioactivity appeared in the bone lipid as soon as 12 h after feeding, with the species rich in bone lipid incorporating the highest activity relative to the flesh. Roughly 80% of the radioactivity recovered in A. fimbria bone lipid was found in triglyceride. Radioactivity was equally distributed between phospholipid and triglyceride in P. pulchrum bone lipids. The results suggest that in some marine fish the bones contain the majority of the organism's reserve energy.