Scorpaenidae Research Articles

Sequence diversity at cytochrome oxidase 1 (Co-1) gene among sculpins (Scorpaeniformes, Cottidae) and some other scorpionfish of Russia Far East with phylogenetic and taxonomic insights

Mitochondrial DNA (mtDNA) atCo-1 gene region was sequenced for 7 scorpion fish species (in total, 16 sequences of at least 552 bp) from the Far East of Russia and compared with 15 other sequences of Scorpaeniformes comprising altogether 29 scorpion-like fish sequences and two outgroup sequences (Cypriniformes). The analysis of the protein-codingCo-1 gene revealed statistically substantiated bias in the (T+C) ∶ (A+G) content, proving basic findings. The average scores ofp-distances for different scales of the evolutionary history atCo-1 gene revealed a clear pattern of increased nucleotide diversity at four different levels: (1) intraspecies, (2) intragenus, (3) intrafamily, and (4) intraorder. The scores of averagep-distances for the compared fish groups were: (1) 1.00±0.20%, (2) 3.80±0.20%, (3) 12.40±1.20%, and (4) 18.00±0.38%, respectively (mean±SE). These data support the concept that speciation in the order Scorpaeniformes, in most cases, follows a geographic mode through accumulation of numerous small genetic changes over a long period of time. However, intraspecies diversity was surprisingly high among scorpionfish. Phylogenetic trees for 29 sequences of scorpionfish and 2 other fishes belonging to ray-finned fishes (Actinopterigii) were developed usingCo-1 gene and four different analytical approaches: Bayesian (BA), maximum likelihood (ML), neighbour-joining (NJ), and maximum parsimony (MP). The analysis revealed a monophyletic origin for the representatives of Cottidae, which is the principal scorpionfish family investigated (100, 96, 98% support level in our BA, MP, and NJ analyses). Similarly, the monophyletic origin of up to the three compared scorpion-like fish genera was supported by molecular phylogenetic data. Species identification on individual basis (barcoding tagging) was high. A few taxonomic complications arose during the analysis and they are discussed here in.

Shallow genetic and morphological divergence among seaperches in the South Pacific (family Scorpaenidae; genus Helicolenus)

The phylogenetic relationships among populations of seaperch, Helicolenus spp., in the south-west Pacific were examined with mtDNA markers. Parts of the cytochrome b gene [459 base pair (bp)] and the control region (448 bp) were sequenced in 58 specimens from the south-west Pacific and four specimens of Helicolenus lengerichi from Chile. Only one clade was recognized in New Zealand coastal waters, despite a wide range of colour morphs. This clade also occurred in the mid Tasman Sea on the Norfolk Ridge and around Tasmania and Victoria. A second sympatric clade was identified around Tasmania and Victoria and to the west of New Zealand. A third allopatric clade was identified to the north of New Zealand and in deep water on the Chatham Rise and a fourth clade on the Foundation Seamounts and the Louisville Ridge. Helicolenus lengerichi from Chile formed a fifth clade. Assuming a molecular clock, the clades were estimated to have diverged c. 0.7-2.6 million years ago. Only two clades, around Tasmania and Victoria, were separated using morphology, colour (in live) and dorsal-fin soft ray counts and were confirmed as Helicolenus percoides and Helicolenus barathri. Two characters, orbit diameter and colour variation, previously used to identify two species in New Zealand waters were unreliable characters for species discrimination. Principle component analyses of 11 morphological measures from 67 individuals did not delineate the clades. A canonical discriminant analysis was able to separate four of the five clades, but mean discriminate probabilities were low (77.6%), except for the five Chilean specimens of H. lengerichi (100%).

A record of Sebastes schlegelii Hilgendorf, 1880 from Dutch coastal waters

Abstract Sebastes schlegelii , a western Pacific rockfish species, is reported for the first time for The Netherlands. The presence of an established population is possible and warrants further investigation. Key words : Sebastes schlegelii , rockfish, Scorpaenidae, exotic species In Dutch marine waters, non-indigenous species from the western Pacific are relatively common. Most of these species were first observed after 1964, when Pacific oysters ( Crassostrea gigas (Thunberg, 1793)) were imported into Europe (Wolff 2005). Among these Pacific species no fish species have yet been reported. Sebastes schlegelii Hilgendorf, 1880, a western Pacific rockfish species, caught in 2008 in the south-western coastal waters of The Netherlands represents the first example. The genus Sebastes , containing the rockfishes, is the most species-rich genus in the family Scorpaenidae (Teleostei: Scorpaeniformes) with approximately 110 species worldwide. Their highest diversity is in the North Pacific (Kai et al. 2003; Hyde and Vetter 2007). The rockfishes exhibit a great diversity in their morphology and ecology, exploiting coastal habitats ranging from shallow rocky areas to depths of about 1000 meters (Love et al. 2002; Nakabo 2002). Only four species are found in the North Atlantic:

Effect of Factors Separated from the Venoms of Scorpion and Jelly Fish on Fertility in Immature Male Mice

El-Sawi, N.M. 2007. Effect of factors separated from the venoms of scorpion and jelly fish on fertility in immature male mice. J. Appl. Anim. Res., 32: 85–88. Bradykinin potentiating factors (BPF) from 2 sources, Egyptian scorpion (Leiurus quinquistriatus) and Jelly fish (Cassiopea andromeda) were injected intraperitoneally as a single dose (24 h). Amplification with bradykinin B2 receptor—specific primers, gave a single 739 bp product from cRNA. The amount of BK expression increased distinctly after injection of scorpion and jelly fish venom. Both factors induced an increase in the level of testosterone hormone and number of interstitial cells. The results suggested that these 2 extracts might be effective in improvement of the infertility patients.

Features of reproductive biology in two tropical fish species from the family Scorpaenidae

Composition of the urogenital system, oocyte development, gamete morphology, and features of embryonic development are described in Scorpaenopsis possi and Sebastapistes cyanostigma (Scorpaenidae) from the Nha Trang Bay, the South China Sea (Vietnam). In males of both species, paired spermiducts enter into the anterior dorsal part of the hypertrophied urinary bladder containing mature sperm. The duration of progressive movements of spermatozoa obtained from the testes and urinary bladder is 5–6 and 12–15 min after activation, respectively. Ovulated oocytes possess oval shapes, they are transparent and without oil droplets. The oocytes are embedded into the floating gelatinous matrix. Insemination of the eggs in nature is apparently external. The embryos of S. cyanostigma hatch at a more advanced morphological condition in comparison to the embryos of Sc. possi. The features of reproductive biology are discussed in the context of the evolution of viviparity within the family.

Casting the Percomorph Net Widely: The Importance of Broad Taxonomic Sampling in the Search for the Placement of Serranid and Percid Fishes

The limits and relationships of serranid and percid fishes, in the context of the percomorph radiation, were resolved using 4036 aligned base pairs of mitochondrial and nuclear DNA sequence data for 180 acanthomorph species. Representatives of all major serranid and percid lineages were analyzed along with 91 additional families from six acanthomorph orders and 25 suborders. Percidae was recovered as monophyletic, and the traditional Serranidae was recovered as polyphyletic, forming five clades: Niphon, Acanthistius, Epinephelinae (less Niphon), Anthiinae (less Acanthistius and Zalanthias kelloggi [formerly included in Plectranthias]), Serraninae (including Zalanthias kelloggi). These traditional “percoid” families were separated from all other “percoid” taxa and recovered within a clade composed of the mail-cheeked fishes and their allies. Based on the evidence provided in this molecular study and prior morphological studies, we recommend taxonomic changes to the Perciformes, Percoidei, Trachinoidei, and Serranidae, we resurrect the Epinephelidae and Niphonidae, and we create a new group, the Moronoidei, to reflect our recovered relationships.

Effect of Trachelobdella lubrica (Hirudinea: Piscicolidae) on biochemical and haematological characteristics of black scorpion fish (Scorpaena porcus, Linnaeus 1758)

Black Scorpion fish (Scorpaena porcus Linnaeus 1758) caught during monthly sampling carried out in 2003 in the Dardanelles, Turkey, were examined for the parasite. Trachelobdella lubrica. Infested fish were caught only during December 2003, and the clinical conditions of the 12 fish naturally infested with T. lubrica included fin rot, swollen foci of skin and haemorrhages of the gill and abdominal skin. The prevalence, intensity and abundance of infestation in December 2003 were 40%, 1.75 and 0.70, respectively. The average hepatosomatic index of the infested fish was lower than that of noninfested fish, while the means of the kidney index, splenosomatic index, condition factor, body weight and length were not significantly different between the infested and noninfested fish groups. Blood analysis was conducted on 12 naturally infested and 12 healthy (noninfested) Black Scorpion fish to determine the possible characteristic changes in blood parameters of the fish in response to natural infestation with T. lubrica. Blood leucocyte counts, haematocrit levels, serum total protein, albumin phosphorus, urea, glucose, globulin, cholesterol and triglyceride concentrations in naturally infested Black Scorpion fish were significantly less than those of the noninfested fish (p < 0.05). No significant decreases were observed in the serum sodium, iron, calcium, potassium, chlorine, blood urea nitrogen and creatinine values of the naturally infested fish. Blood haemoglobin values, erythrocyte counts and serum glutamate aspartate aminotransferase (glutamate oxalacetate transaminase), alanine aminotransferase (glutamate pyruvate transaminase), uric acid and very low-density lipids levels of infested fish were insignificantly greater than those in healthy fish.

Fatty acid profiles of commercially important fish species from the Mediterranean, Aegean and Black Seas

The fat content and fatty acid compositions in the flesh of eight commercially important fish species from the seas of Turkey were evaluated. The fatty acid compositions of wild fish species ranged from 25.5% to 38.7% saturated (SFA), 13.2–27.0% monounsaturated (MUFAs) and 24.8–46.4% polyunsaturated acids (PUFAs). Among them, those occurring in the highest proportions were myristic acid (C14:0, 1.70–10.9%), palmitic acid (C16:0, 15.5–20.5%), palmitoleic acid (C16:1, 2.86–17.0%), stearic acid (C18:0, 3.32–8.18%), oleic acid (C18:1 n9 cis, 6.11–20.8%), linoleic acid (C18:2 n6, 0.93–4.03%), octadecatetraenoic acid (C18:4 n3, 0.02–4.55%), cis-5, 8, 11, 14, 17-eicosapentaenoic acid (EPA, C20:5 n3, 4.74–11.7%) and cis-4, 7, 10, 13, 16, 19-docosahexaenoic acid (DHA, C22:6 n3, 7.69–36.2%). The proportions of PUFAs- n3 (ranging from 21.7 for mullet to 43.7 for scad) were higher than those of PUFAs- n6 (ranging from 1.24 for bogue to 4.34 for red scorpion fish). EPA and DHA were high in all fish species, increasing the value of these fish species.

Sperm nuclear basic proteins of two closely related species of scorpaeniform fish (Sebastes maliger, Sebastolobus sp.) with different sexual reproduction and the evolution of fish protamines

In this paper, we present a review of sperm nuclear basic proteins (SNBPs) in teleost fish. The distribution of the three basic groups of SNBPs [histone (H)-type, protamine-like (PL)-type and protamine (P)-type], their evolution and possible relation to the mode of fertilization are described. In this regard, we have characterized the SNBPs from two closely related species of Scorpaeniform fish: internally fertilizing Sebastes maliger and externally fertilizing Sebastolobus sp., both in the family Scorpaenidae. Despite the different reproductive behavior of these two closely related rockfish species, in both instances the SNBP consists of protamines. However, there is a significant increase in the arginine content of the protamine in the internally fertilizing rockfish. The relevance of this observation is discussed within the context of the P-type SNBP in teleosts. The rapid evolution of teleost protamines, including those in rockfish, has also allowed us to obtain a molecular phylogeny for this group of bony fish that is almost indistinguishable from that currently available from the use of conventional anatomical/paleontological markers.

Biomonitoring of the coastal waters of the Black Sea

Morpho-physiological and biochemical parameters were determined in Scorpion fish Scorpaena porcus L. from two bays in the area of Sevastopol, which experience a high anthropogenic load. The effect of natural and anthropogenic factors on the size, weight, and age composition, as well as on the sex ratio of the fish from both populations, was studied. The relationships between the concentrations of chlororganic substances in the water of the bays, their accumulation in the liver and gonads of the fish, the activity of antioxidant enzymes in the blood, and the fractional composition of serum proteins were determined. A possibility for the use of the Scorpion fish as a indicator species for the biomonitoring and assessment of the environmental conditions in the coastal waters of the Black Sea was considered.

Anatomical description and phylogenetic classification of the orbicular velvetfishes (Scorpaenoidea: Caracanthus)

Anatomical characters for two species of the orbicular velvetfishes (Caracanthus) are described, and the phylogenetic position of the genus among the superfamily Scorpaenoidea is estimated cladistically on the basis of morphological characters belonging to 112 transformation series. Caracanthus is nested within the family Scorpaenidae, having close relationships with Taenianotus and Pteroidichthys. Validity of the family Caracanthidae was not supported, Caracanthus being included within the Scorpaenidae.

Distribution of NGF and NT‐3‐like protein immunoreactivity in the teleost kidney

By means of immunochemistry and immunohistochemistry, we investigated in the kidney of freshwater and marine teleostean species for the presence and localization of three neurotrophins: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin (NT)-3. In both species studied, NGF-like and NT-3-like immunoreactivity were present in the kidney with different distribution patterns, while BDNF-like immunoreactivity was never detected. In goldfish, NGF-like and NT-3-like immunoreactivity were identified extensively in cells along part of the arterial branches adjacent to the afferent arterioles. In scorpion fish, NGF-like and NT-3-like immunoreactive cells were observed both on afferent arterioles and on adjacent secondary branches derived from renal arteries. No immunoreactivity was detected in other renal structures. A staining pattern of immunoreactivity similar to that obtained for NGF and NT-3 was detected utilizing S100 antibody as a juxtaglomerular (JG) cell marker. Double immunolabellings NGF/S100 and NT-3/S100 evidenced the coexistence of neurotrophin-like proteins and S100-like protein in the same immunoreactive cells, thus identifying them as juxtaglomerular cells. Western blot analysis revealed the presence of molecules immunoreactive to NGF and NT-3, whose molecular weights were very similar to those of the corresponding mammalian neurotrophins. These findings extend the presence and distribution of NGF-like and NT-3-like IR in the kidney to teleost species, suggesting a probable participation of these proteins in the renal functions of freshwater and marine teleosts.

Spatial and temporal variation in the diet of a high trophic level predator, the Australian fur seal ( Arctocephalus pusillus doriferus )

This study quantifies the manner in which Australian fur seals, Arctocephalus pusillus doriferus, use their prey in a spatial and temporal context. We analysed 977 scat and 66 regurgitate samples collected from Tasmanian breeding colonies and haul-outs between 1994 and 2000. Diagnostic prey remains identified in the scats represented 35 fish taxa and 8 cephalopod taxa. The main taxa identified in scats, where frequency of occurrence was ≥10%, were leatherjacket species (family Monocanthidae), redbait (Emmelichthys nitidus), barracouta (Thyrsites atun), jack mackerel (Trachurus declivis) and red cod (Pseudophysis bachus). Regurgitates were dominated by cephalopods, primarily Gould’s squid (Nototodarus gouldi), Octopus maorum, O. berrima/pallidus and Sepia apama. Discriminant function analyses indicated that there were generally no significant differences in the composition of the diet between colonies within a year, suggesting that prey distribution is fairly uniform throughout Bass Strait at those time scales. The diet at breeding colonies, however, exhibited significant inter- and intra-annual variation, determined by the presence of several key taxa, such as barracouta and a species of scorpionfish (family Scorpaenidae). The diet composition also varied regionally, between Bass Strait and southern Tasmania in spring 1999 and autumn 2000, with redbait, barracouta and a species of scorpionfish identified as the main taxa contributing to this difference. Redbait occurred in the diet only in southern Tasmania, whereas barracouta and scorpionfish occurred only in Bass Strait.

Injuries caused by scorpionfishes ( Scorpaena plumieri Bloch, 1789 and Scorpaena brasiliensis Cuvier, 1829) in the Southwestern Atlantic Ocean (Brazilian coast): epidemiologic, clinic and therapeutic aspects of 23 stings in humans

Fishes of the family Scorpaenidae are responsible for severe injuries and occasionally deaths in humans around the world. The more venomous fishes on the Brazilian coast and in the Southwestern Atlantic region are classified in the genus Scorpaena (family Scorpaenidae). However, there are few studies on the venomous apparatus, the effects of the venom, or clinical aspects of human envenoming provoked by Atlantic scorpionfishes. In this communication, the authors present 23 accidents caused by scorpionfishes of the genus Scorpaena among fishermen, and report the species that provoked the injuries, the circumstances of contacts, the clinical aspects observed and the therapeutic measures utilized for control of the symptoms of the victims. The intense pain and the systemic findings observed in the patients were very frequent and we think that the injuries provoked by scorpionfishes should be considered the most important manifestations caused by venomous fishes of the East Atlantic Ocean.

Composition of pâtés elaborated with mackerel flesh ( Scomber scombrus) and tuna liver ( Thunnus thynnus): comparison with commercial fish pâtés

Three types of pâtés manufactured with different quantities of tuna liver ( Thunnus thynnus) and mackerel flesh ( Scomber scombrus) were developed, in order to use these low-cost raw materials. Their nutritional value was compared with commercial fish pâtés made of tuna, large-scaled scorpion fish ( Scorpaena scrofa), salmon ( Salmo salar) and anchovy ( Eugraulis encrasicholus). In relation to the general composition, no relevant differences were found between experimental and commercial products, except for the fat content, which was lower in the commercial products made of tuna and large-scaled scorpion fish. Commercial pâtés in general showed higher salt contents. The fatty acid profiles of commercial pâtés showed higher unsaturated/saturated and polyunsaturated/saturated ratios. The contents of omega-3 fatty acids were as follows: eicosapentaenoic acid (EPA) ranged from 0.02 to 0.27 g/100 g in commercial products and from 0.22 to 0.36 g/100 g in experimental pâtés and docosahexaenoic acid (DHA) ranged from 0.07 to 0.50 g/100 g in the different commercial products and from 0.6 to 0.83 g/100 g in experimental fish pâtés. Commercial products showed higher omega-6/omega-3 ratios, due to the lower contents of EPA and DHA and the higher content of linoleic acid, as a result of the addition of vegetable oils in this type of product. Although a strong fishy taste was detected on sensory analysis of experimental pâtés, all of them were considered to be acceptable.

Gametogenesis of Helicolenus dactylopterus dactylopterus (Teleostei, Scorpaenidae)

Helicolenus dactylopterus dactylopterus is a zygoparous species with internal fertilization. Within the family Scorpaenidae, it occupies an intermediate position between strictly ovuliparous species and viviparous ones. This article describes all stages in the development of the germ cells, using both light and electron microscopy, with especial emphasis on those morphological features that may be significant in zygoparous reproduction. Characteristic features of oogenesis include the paucity and small size of the cortical alveoli, and the zona radiata being less thick. Moreover, lipid droplets are detected from the beginning of the primary growth phase. The elongation of the spermatic nucleus and of the middle piece which occurs during spermatogenesis is characteristic of the transport and storage of sperm in internally fertilizing species. No intraovarian embryos have been detected, so spawning probably takes place shortly after fertilization. Gametogenèse d' Helicolenus dactylopterus dactylopterus (Teleostei: Scorpenidae). Helicolenus dactylopterus dactylopterus est une espèce zygopare avec une fécondation interne. Dans la famille des Scorpaenidae elle occupe une position intermédiaire entre les espèces strictement ovipares et les espèces vivipares. Cet article décrit les stades de développement des cellules germinales, àla fois en microscopie photonique et électronique, en insistant sur les traits morphologiques particuliers àce type de reproduction. Les particularités de l'ovogenèse concernent la raretéet la petite taille des alvéoles corticales, ainsi que la l'épaisseur réduite de la zona radiata. De plus des gouttelettes lipidiques sont détectées dès les phases initiales de la première phase de croissance. L'élongation du noyau spermatique et de la pièce intermédiaire, qui se produisent durant la espermatogenèse, sont liés au transfert et àla conservation du sperme chez les espèces àfécondation interne. L'absence d'embryons dans l'ovaire suggère que la ponte a lieu rapidement après la fécondation.

Les animaux aquatiques dangereux

Risks of envenoming due to aquatic animals are very diversified. They occur in swimmers, divers and fishermen. They are due to three mechanisms : cutaneous contacts, stings and bites. The venoms are mostly neurotoxic, cardiotoxic and paralysing. — Envenoming by contact with the skin is due to stinging cells (or nematocysts). Such venomous animals are jelly fishes, corals and sea-anemones. Treatment is only symptomatic. Specific antivenin for Chironex fleckerii is available only in Australia. • — Envenoming by stings occur with molluscs (conus) and echinoderms (sea urchins, sunstars) and some fishes (rays, weever-fishes, scorpion fishes, Pterois, silurus, catfishes). These venoms are thermolabile. Treatment of wounds is local (cleaning of all debris) and general in case of diffuse reactions. Stone-fish specific antivenin is available only in Australia. • — Envenoming by bites is caused by piranhas, muraena, some sea snakes and mostly sharkes. Wounds are severe and sometimes fatal. Prevention of these envenoming consists in avoiding the contacts with such aquatic animals when diving and when handling them, even when they are justed catched and pinched in the fishing nets. Treatment is mostly symptomatic, and sometimes in intensive care unit.

Study of mitogenic/cytotoxic effects of venom proteins from Scorpion fish S. verrucosa and H. rubripinnis, on normal and tumor cell lines, using flow cytometer

Study of mitogenic/cytotoxic effects of venom proteins from Scorpion fish S. verrucosa and H. rubripinnis, on normal and tumor cell lines, using flow cytometer

Baseline respiration and spontaneous activity of sluggish marine tropical fish of the family Scorpaenidae

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 219:229-239 (2001) - doi:10.3354/meps219229 Baseline respiration and spontaneous activity of sluggish marine tropical fish of the family Scorpaenidae Christopher Zimmermann1,2,*, Andreas Kunzmann1,3 1Institut für Polarökologie der Universität Kiel, Wischhofstr. 1-3, Geb. 12, 24148 Kiel, Germany 2Institut für Seefischerei, Bundesforschungsanstalt für Fischerei, Palmaille 9, 22767 Hamburg, Germany 3Zentrum für Marine Tropenökologie, Universität Bremen, Fahrenheitstr. 6, 28359 Bremen, Germany *E-mail: czimmermann@ipoe.uni-kiel.de ABSTRACT: Baseline respiration and spontaneous activity were determined simultaneously for 6 specimens of tropical scorpionfishes, belonging to 2 different genera: Scorpaenopsis oxycephalus and S. diabolus (false stonefish) and Parascorpaena sp. and P. aurita. The experiments were conducted in an intermittent-flow respirometer at 24°C, at ambient light regime (12 h dark: 12 h light) and salinity (S = 32). Permanent measurements of fish activity by an infrared video system (number of movements) and oxygen consumption were coupled allowing the calculation of a standard oxygen consumption (SOC) rate. The experimental set-up allowed quantification of spontaneous activity. Relative SOC values varied between 32.3 mg O2 h-1 kg-1 wet mass (wm) for a large S. oxycephalus (82 g WM) and 68.9 mg O2 h-1 kg-1 WM for the smallest investigated specimen, a P. aurita (16 g WM). The latter also showed the highest spontaneous activity rate (mean 98 movements h-1; max.: 870 h-1), while the values for the most sluggish individual did not exceed 24.6 h-1 (mean) and 480 h-1 (max.), respectively. Absolute SOC for a standard mass of 50 g was calculated to be 2.0 mg O2 h-1, using a wet mass versus oxygen consumption relationship of SOC (mg O2 h-1) = 0.26 x WM(g)0.527. The tropical scorpionfish investigated are some of the most sluggish fish found on coral reefs, with activity levels (means and variance) similar to that of boreal or polar scorpaenids (e.g. sculpins). In this respect, there was no indication for any specific adaptation to temperature. Baseline oxygen consumption values of the fish in this study were the lowest recorded for marine tropical species, and a first rough comparison of the resting metabolism of scorpaenid fish over a wide range of environmental temperatures might indicate a reduced thermal sensitivity of the tropical fish investigated. KEY WORDS: Respiration · Standard oxygen consumption · Spontaneous activity · Coral reefs · Scorpionfishes · Scorpaenidae Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 219. Online publication date: September 10, 2001 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2001 Inter-Research.

Essentiality of dietary calcium supplement in fingerling scorpion fish ( Sebastiscus marmoratus)

Essentiality of dietary calcium (Ca) supplement was investigated in fingerling scorpion fish. Four purified diets were formulated with supplementation of 0.2% Ca from Ca-lactate, no supplemental Ca, and 0.2 and 2.5% Ca from tricalcium phosphate (TCP), respectively. Each experimental diet was fed to three replicate groups of fish (mean weight, 0.8 g) for 12 weeks at a water temperature of 24±0.2°C. Significantly lower weight gain was observed in fish fed the Ca-unsupplemented diet compared to the control diet with 0.2% Ca supplement from Ca-lactate. The growth of fish fed the diet with a low level (0.2%) of Ca from TCP was similar to that of fish fed the control diet. However, a high level (2.5%) of dietary Ca from TCP significantly decreased growth. Calcium and phosphorus contents in whole body and vertebrae were similar in fish fed all the diets. A high level of dietary Ca from TCP decreased some trace elements in whole body, liver and vertebrae. Results suggest that scorpion fish do not obtain adequate Ca from seawater for normal growth and a dietary Ca supplement is necessary. Although this species can use a low level of dietary TCP as a source of Ca for growth, excessive dietary TCP depresses growth and negatively affects the contents of some trace elements in tissues. Readily available Ca (mono- or dibasic Ca) supplement to the diet appears to be essential for optimum growth and for maintaining normal mineral levels in tissues of scorpion fish.