scholarly journals Weaning of Burbot, Lota lota (L.) from Live to Dry Feed Using NaCl as Dietary Attractant

2017 ◽  
Vol 9 (3) ◽  
pp. 7
Author(s):  
Franz Lahnsteiner ◽  
Manfred Kletzl
Keyword(s):  
Body Mass ◽  
Sedimentation Rate ◽  
Condition Factor ◽  
Mortality Rates ◽  
Hepatosomatic Index ◽  
Lota Lota ◽  
Live Feed ◽  
Feeding Experiments ◽  
Feeding Attractant ◽  
Weaning Protocols

Weaning of 150 days post hatch Lota lota from live feed (zooplankton) to formulated dry feed (FDF) was investigated. L. lota could not be forced from live feed to FDF. They refused FDF for periods up to 21 d. Body mass decreased for 20%, condition factor for 15%, and hepatosomatic index for 50%. In 21 days lasting co-feeding experiments with FDF and live feed L. lota selected exclusively the live feed organisms. NaCl in a concentration of 5% was a dietary feeding attractant for L. lota. When FDF was supplemented with 5% NaCl, L. lota could be abruptly weaned from live to dry feed. During a 21 d lasting experiment body mass increased for circa 40%, total length for 10%, condition factor for 5% and hepatosomatic index remained constant. These values were similar to live zooplankton feeding. However, increased mortality of > 20% was recorded for fish fed with the 5% NaCl containing FDF. To reduce mortality FDF was supplemented with zooplankton meal to upgrade its quality and extruded to optimize its density and sedimentation rate. With the adjusted FDF mortality rates were reduced to < 5%. Using the optimized dry feed easy and sustainable weaning protocols were developed where NaCl and zooplankton meal were gradually reduced to adapt fish to pure FDF.

Condition and energy reserves of Atlantic cod (Gadus morhua) during the collapse of the northern Gulf of St. Lawrence stock

1997 ◽  
Vol 54 (10) ◽  
pp. 2388-2400 ◽  
Author(s):  
Y Lambert ◽  
J -D Dutil
Keyword(s):  
Seasonal Variations ◽  
Gadus Morhua ◽  
Condition Factor ◽  
Atlantic Cod ◽  
Hepatosomatic Index ◽  
Seasonal Cycles ◽  
Interannual Variations ◽  
Energy Reserves ◽  
Tissue Composition ◽  
Feeding Experiments

Interannual variations and seasonal cycles in condition and energy reserves were investigated for the northern Gulf of St. Lawrence cod (Gadus morhua) before and during the collapse of the stock. Significant decreases in cod condition between the late 1980s and the early 1990s coincided with the reduction in biomass. Cod exhibited clear seasonal variations in condition factor (Fulton's K), energy reserves, and tissue composition. Maximum K (0.87-0.91) and highest hepatosomatic index (HSI; 4.3-5.7%) occurred during the autumn while minimum levels occurred in spring. In May, the levels of condition (K, 0.69-0.74; HSI, 2.2-3.0) were below those reported for other stocks. In spring during spawning, a proportion of the wild cod had condition and energy reserves that were within the range that resulted in mortality among unfed fish held in the laboratory. Feeding experiments also indicate that the condition of wild cod in fall was lower than that observed for well-fed fish held in the laboratory. The decline in the condition and energy reserves of cod during several consecutive years may have lowered the productivity of the northern Gulf of St. Lawrence stock. This, along with overfishing, could have contributed to the collapse of this stock.

scholarly journals Pathogenicity and Infection Cycle of Vibrio owensii in Larviculture of the Ornate Spiny Lobster (Panulirus ornatus)

2012 ◽  
Vol 78 (8) ◽  
pp. 2841-2849 ◽  
Author(s):  
Evan F. Goulden ◽  
Michael R. Hall ◽  
David G. Bourne ◽  
Lily L. Pereg ◽  
Lone Høj
Keyword(s):  
Fluorescent Protein ◽  
Histopathological Examination ◽  
Single Cells ◽  
Larval Mortality ◽  
Spiny Lobster ◽  
Systemic Infection ◽  
Mortality Rates ◽  
Infection Process ◽  
Content Type ◽  
Live Feed

ABSTRACTThe type strain ofVibrio owensii(DY05) was isolated during an epizootic of aquaculture-reared larvae (phyllosomas) of the ornate spiny lobster (Panulirus ornatus).V. owensiiDY05 was formally demonstrated to be the etiological agent of a disease causing rapid and reproducible larval mortality with pathologies similar to those seen during disease epizootics. Vectored challenge via the aquaculture live feed organismArtemia(brine shrimp) caused consistent cumulative mortality rates of 84 to 89% after 72 h, in contrast to variable mortality rates seen after immersion challenge. Histopathological examination of vector-challenged phyllosomas revealed bacterial proliferation in the midgut gland (hepatopancreas) concomitant with epithelial cell necrosis. A fluorescent-protein-labeledV. owensiiDY05 transconjugant showed dispersal of single cells in the foregut and hepatopancreas 6 h postexposure, leading to colonization of the entire hepatopancreas within 18 h and eventually systemic infection.V. owensiiDY05 is a marine enteropathogen highly virulent toP. ornatusphyllosoma that uses vector-mediated transmission and release from host association to a planktonic existence to perpetuate transfer. This understanding of the infection process will improve targeted biocontrol strategies and enhance the prospects of commercially viable larviculture for this valuable spiny lobster species.

Condition factor and hepatosomatic index as estimates of energy status in male three-spined stickleback

1995 ◽  
Vol 47 (5) ◽  
pp. 775-787 ◽  
Author(s):  
S. Chellappa ◽  
F. A. Huntingford ◽  
R. H. C. Strang ◽  
R. Y. Thomson
Keyword(s):  
Condition Factor ◽  
Hepatosomatic Index ◽  
Energy Status

scholarly journals Morphometric and Physiological Characteristics of Brown Trout (Salmo trutta) from the Ponor River

2017 ◽  
Vol 17 (3) ◽  
pp. 233
Author(s):  
Radoslav Dekić ◽  
Maja Manojlović ◽  
Jasna Friščić ◽  
Svjetlana Lolić ◽  
Dragojla Golub
Keyword(s):  
Body Mass ◽  
Body Length ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Condition Factor ◽  
Hematological Parameters ◽  
Hemoglobin Concentration ◽  
Mean Corpuscular Hemoglobin ◽  
Average Value ◽  
Brown Trout Salmo Trutta

This paper presents the data related to morphometric and physiological (hematological) characteristics of brown trout (Salmo trutta) from the Ponor River. This river rises near the village Podrašnica (municipality of Mrkonjić Grad), sinks above the ground and after a while, near the settlement of Krupa na Vrbasu, appears as a source of the Krupa River (tributary of the Vrbas River). Fish sampling was performed during the summer of 2015 and during this period 22 Salmo trutta units were caught (11 females and 11 males). On that occasion, several morphometric (total and standard body length) and hematological traits (Hct-hematocrit, Hb-hemoglobin and MCHC - mean corpuscular hemoglobin concentration), body mass and Fulton’s condition factor were analyzed. The average value for total body length was 18.85 cm and for standard body length it was 16.85 cm; the mean value for body mass was 80.38 g, and for Fulton’s condition factor 1.41. In case of hematological parameters, the average value for Hct was 0.39 l/l, Hb 70.62 g/l and MCHC 180.64 g/l erythrocytes. The estimated parameters can serve as indicators for the condition of these aquatic organisms, and indirectly, the state of their environment.

Small-scale temporal and spatial variation in Atlantic cod (Gadus morhua) life history

2003 ◽  
Vol 60 (9) ◽  
pp. 1111-1121 ◽  
Author(s):  
Tara M McIntyre ◽  
Jeffrey A Hutchings
Keyword(s):  
Body Mass ◽  
Life Histories ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Spatial Scales ◽  
Gonadosomatic Index ◽  
Small Scale ◽  
Hepatosomatic Index ◽  
Georges Bank ◽  
High Fecundity

Life histories of Atlantic cod (Gadus morhua) from the Gulf of St. Lawrence south to Georges Bank differ significantly through time and space. Within the Southern Gulf, fecundity per unit body mass differed by more than 40% over short (2 years) and long (42–45 years) periods of time. Significant variation in size-specific fecundity is also evident among populations: Southern Gulf cod produce almost 30% more eggs per unit body mass than those on Georges Bank, whereas fecundity of Scotian Shelf cod is almost half that of cod in Sydney Bight. Compared with those on Georges Bank, Southern Gulf cod life histories are characterized by high fecundity, late maturity, high gonadosomatic index, and large eggs. Relative to the influence of body size, neither temporal nor spatial differences in fecundity can be attributed to physiological condition, as reflected by liver weight, hepatosomatic index, and Fulton's K. Delayed maturity and higher reproductive allotment among Southern Gulf cod can be explained as selection responses to slower growth, higher prereproductive mortality, and fewer lifetime reproductive events. Patterns of covariation in heritable, fitness-related traits suggest the existence of adaptive variation and evolutionarily significant units at spatial scales considerably smaller than the species range in the Northwest Atlantic.

scholarly journals No gastric mill in sauropod dinosaurs: new evidence from analysis of gastrolith mass and function in ostriches

2006 ◽  
Vol 274 (1610) ◽  
pp. 635-640 ◽  
Author(s):  
Oliver Wings ◽  
P. Martin Sander
Keyword(s):  
Body Mass ◽  
Digestive System ◽  
Gastric Mill ◽  
Theropod Dinosaurs ◽  
Feeding Experiments ◽  
Stem Lineage ◽  
Order Of Magnitude ◽  
Food Retention ◽  
And Function ◽  
New Evidence

Polished pebbles occasionally found within skeletons of giant herbivorous sauropod dinosaurs are very likely to be gastroliths (stomach stones). Here, we show that based on feeding experiments with ostriches and comparative data for relative gastrolith mass in birds, sauropod gastroliths do not represent the remains of an avian-style gastric mill. Feeding experiments with farm ostriches showed that bird gastroliths experience fast abrasion in the gizzard and do not develop a polish. Relative gastrolith mass in sauropods (gastrolith mass much less than 0.1% of body mass) is at least an order of magnitude less than that in ostriches and other herbivorous birds (gastrolith mass approximates 1% of body mass), also arguing against the presence of a gastric mill in sauropods. Sauropod dinosaurs possibly compensated for their limited oral processing and gastric trituration capabilities by greatly increasing food retention time in the digestive system. Gastrolith clusters of some derived theropod dinosaurs (oviraptorosaurs and ornithomimosaurs) compare well with those of birds, suggesting that the gastric mill evolved in the avian stem lineage.

scholarly journals Reproductive Phenology and Size Structure Characteristics of Hypseleotris agilis (Herre, 1927) in Lake Mainit, Philippines

2020 ◽  
Vol 80 ◽  
pp. 35-42
Author(s):  
Joycelyn C. Jumawan ◽  
Paula Marie Hidalgo ◽  
Romell A. Seronay
Keyword(s):  
Native Species ◽  
Condition Factor ◽  
Size Structure ◽  
Gonadosomatic Index ◽  
Reproductive Phenology ◽  
Hepatosomatic Index ◽  
Fishery Resource ◽  
Gravid Females ◽  
Management And Conservation

Hypseleotris agilis locally known as Bugwan is a native species and one of the most abundant fishes of commercial value in Lake Mainit, Philippines. A total of 1,584 H. agilis from Lake Mainit near the mouth of Kalinawan and Puyo River were caught from May 2018 to February 2019 to determine the length-weight relationship (LWR), condition factor (K), gonadosomatic index (GSI) and hepatosomatic index (HSI) of this species. Positive allometric growth was observed for both sexes (b>3). Sex ratio indicated the dominance of males over females as much as 58.7%. The number of ripe males and gravid females was observed throughout the months of the collection, which indicates the ability of the fish species to spawn continuously throughout the year. Determination of GSI in both sexes showed higher values during November (males) and December (females). However, HSI values were relatively low during the spawning season, which would indicate the usage of energy for gonadal maturation. The K factor showed high values during the peak spawning months, directly proportional to GSI values. This study provides updated information for management and conservation of this important fishery resource in Lake Mainit.

scholarly journals Integrating plant stoichiometry and feeding experiments: state-dependent forage choice and its implications on body mass

Oecologia ◽  
2021 ◽  
Author(s):  
Juliana Balluffi-Fry ◽  
Shawn J. Leroux ◽  
Yolanda F. Wiersma ◽  
Isabella C. Richmond ◽  
Travis R. Heckford ◽  
...  
Keyword(s):  
Body Mass ◽  
Feeding Experiments ◽  
State Dependent

Reproductive cycle of the blue jack mackerel, Trachurus picturatus (Bowdich, 1825), off the Portuguese continental coast

2019 ◽  
Vol 32 ◽  
pp. 14
Author(s):  
Ana Maria Costa
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Stock Assessment ◽  
Gonadosomatic Index ◽  
Biological Information ◽  
Hepatosomatic Index ◽  
Jack Mackerel ◽  
First Time ◽  
Monthly Variations

This work provides for the first time a description of the reproductive biology of Trachurus picturatus in Portuguese continental waters (between 41° 49′ and 36° 57′ latitude North). From January 2010 to December 2016 a total of 7409 individuals were sampled from bottom trawlers operating on the northwestern coast of Portugal. The observed sex ratio was 0.56 in favor of the females. Monthly variations in gonadosomatic index, proportion of actively spawning individuals, hepatosomatic index and Fulton′s condition factor were analyzed. More than 60% of spawning individuals were recorded in the first quarter, corresponding to the highest values of GSI, and Fulton's K and hepatosomatic index increased after the start of spawning. The morphometric relationships between total length and gutted weight showed significant correlations (high determination coefficient, r2 > 0.9) and isometric growth (b = 3) for both sexes. Results indicate that the spawning season of T. picturatus starts in December and extends until April–May, with a peak in March, which agrees with what has been indicated by other authors for the northeast Atlantic. This work provides important biological information on a species that although not subject to stock assessment is currently the 5th species landed by weight in Portuguese continental waters.

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