A recirculation system for the experimental hatchery-rearing of turbot (<i>Scophthalmus maximus</i>) larvae

A new pilot hatchery was constructed with the aim to develop an operational system for larval nutrition studies with various fish species. Special attention was paid to develop independent rearing units, including a separate biofilter section, similar to the setups used for crustacean larviculture. The idea was to create optimal and reproducible rearing conditions on a laboratory scale, providing the possibility to test various nutritional treatments simultaneously

Optimized feeding strategies in the larviculture of the Asian seabass <i>Lates calcarifer</i>

This paper reports on the progress made at the Tigbauan hatchery of SEAFDAC in the Philippines, with the larviculture of the Asian seabass Lates calcarifer when using w3-HUFA enriched Brachionus and Artemia .In order to optimize the transitions of the different prey types, larval mouth size was analyzed as a function of larval development: San Francisco Bay (SFB) type Artemia nauplii can be ingested from days 8 to 10 onwards, and Great Salt Lake (GSL) nauplii from days 10 to 15 (with some variations depending on growth differences between culture trials). In view of the high correlation between mouth size and total larval length, the feeding of different size classes of Artemia can be better programmed, i.e., SFB nauplii can be fed when fish larvae measure 4 mm in length, and 24 hr enriched GSL can be given to 7 mm larvae. The incorporation of the HUFA's 20:5w3 and 22:6w3 in the live prey Artemia, and possibly Brachionus, greatly improved larval ability to metamorphose, although it did not affect growth nor survival until day 21. However, when 21 day old fry were subjected to a stress test, much higher survival rates were obtained in HUFA-enriched seabass larvae, illustrating their superior physiological condition over fry cultured with non-enriched Brachionus and Artemia . These findings were used to propose an improved feeding strategy for the larviculture of Lates calcarifer

Enhancement of stress resistance of the guppy <i>Poecilia reticulata</i> through feeding with vitamin C supplement

This study investigated the use of vitamin C supplement in formulated diets and live Artemia juveniles to enhance the stress resistance of the guppy Poecilia reticulata. To evaluate the stress resistance, fish were subjected to osmotic shock in pre-aerated water containing 35 ppt sodium chloride. Ascorbyl acid-poly phosphate and ascorbyl palmitate were used as vitamin C sources for formulated diets and live Artemia juveniles, respectively. Results showed that guppies fed moist formulated diets supplemented with ascorbic acid at 1,000 mg/kg or 2,000 mg/kg diet displayed significantly higher levels of stress resistance than fish fed control formulated diet for 13 d. The stress resistance of fish fed a lower dose (200 mg/kg diet), however, did not differ significantly from that of the control. On the other hand, the stress resistance of guppies fed Artemia juveniles bio-encapsulated with 10% or 20% ascorbyl palmitate did not show significant difference from that of fish fed control Artemia after 20 d. The stress resistance of these three groups of Artemia-fed fish, however, was significantly higher than that of fish fed the control formulated diet. Biochemical analyses showed that raising the ascorbic acid level in feeds resulted in a concomitant increase in the incorporated ascorbic acid level in the whole-body tissue of the guppy. The increased stress resistance of the guppy fed a vitamin C supplemented diet has also been demonstrated in four commercial farms. The potential application of the improved stress resistance in the ornamental fish industry was discussed

Biomechanical assessment of the effects of decompressive surgery in non-chondrodystrophic and chondrodystrophic canine multisegmented lumbar spines

Purpose Dogs are often used as an animal model in spinal research, but consideration should be given to the breed used as chondrodystrophic (CD) dog breeds always develop IVD degeneration at an early age, whereas nonchondrodystrophic (NCD) dog breeds may develop IVD degeneration, but only later in life. The aim of this study was to provide a mechanical characterization of the NCD [non-degenerated intervertebral discs (IVDs), rich in notochordal cells] and CD (degenerated IVDs, rich in chondrocyte-like cells) canine spine before and after decompressive surgery (nucleotomy). Methods The biomechanical properties of multisegmented lumbar spine specimens (T13-L5 and L5-Cd1) from 2-year-old NCD dogs (healthy) and CD dogs (early degeneration) were investigated in flexion/extension (FE), lateral bending (LB), and axial rotation (AR), in the native state and after nucleotomy of L2-L3 or dorsal laminectomy and nucleotomy of L7-S1. The range of motion (ROM), neutral zone (NZ), and NZ stiffness (NZS) of L1-L2, L2- L3, L6-L7, and L7-S1 were calculated. Results In native spines in both dog groups, the greatest mobility in FE was found at L7-S1, and the greatest mobility in LB at L2-L3. Surgery significantly increased the ROM and NZ, and significantly decreased the NZS in FE, LB, and AR in both breed groups. However, surgery at L2-L3 resulted in a significantly larger increase in NZ and decrease in NZS in the CD spines compared with the NCD spines, whereas surgery at L7-S1 induced a significantly larger increase in ROM and decrease in NZS in the NCD spines compared with the CD spines. Conclusions Spinal biomechanics significantly differ between NCD and CD dogs and researchers should consider this aspect when using the dog as a model for spinal research. © Springer-Verlag 2012

Assessment of bone ingrowth potential of biomimetic hydroxyapatite and brushite coated porous E-beam structures

The bone ingrowth potential of biomimetic hydroxyapatite and brushite coatings applied on porous E-beam structure was examined in goats and compared to a similar uncoated porous structure and a conventional titanium plasma spray coating. Specimens were implanted in the iliac crest of goats for a period of 3 (4 goats) or 15 weeks (8 goats). Mechanical implant fixation generated by bone ingrowth was analyzed by a push out test. Histomorphometry was performed to assess the bone ingrowth depth and bone implant contact. The uncoated and hydroxyapatite-coated cubic structure had significantly higher mechanical strength at the interface compared to the Ti plasma spray coating at 15 weeks of implantation. Bone ingrowth depth was significantly larger for the hydroxyapatite- and brushite-coated structures compared to the uncoated structure. In conclusion, the porous E-beam surface structure showed higher bone ingrowth potential compared to a conventional implant surface after 15 weeks of implantation. Addition of a calcium phosphate coating to the E-beam structure enhanced bone ingrowth significantly. Furthermore, the calcium phosphate coating appears to work as an accelerator for bone ingrowth

Quantitative analysis of the anterolateral ossification mass in diffuse idiopathic skeletal hyperostosis of the thoracic spine

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic condition leading to ossification of spinal ligaments and has been shown to behave similarly to ankylosing spondylitis (AS) often leading to unstable hyperextension fractures. Currently, no quantitative data are available on the spatial relationship between the bridging anterolateral ossification mass (ALOM) and the vertebral body/intervertebral disc to explain the propensity in DISH to fracture through the vertebral body instead of through the intervertebral disc as more often seen in AS. Furthermore, no reasonable explanation is available for the typical flowing wax morphology observed in DISH. In the current study, a quantitative analysis of computed tomography (CT) data from human cadaveric specimens with DISH was performed to better understand the newly formed osseous structures and fracture biomechanics. Additionally, the results were verified using computed tomography angiography data from ten patients with DISH and ten controls. Transverse CT images were analyzed to obtain ALOM area and centroid angle relative to the anteroposterior axis; intervertebral disc and adjacent cranial and caudal levels. The ALOM area at the mid-vertebral body level averaged 57.9 ± 50.0 mm2; at the mid-intervertebral disc space level it averaged 246.4 ± 95.9 mm2. The mean ALOM area at the adjacent level caudal to the mid-vertebral body level was 169.6 ± 81.3 mm2; at the adjacent cranial level, it was 161.7 ± 78.2 mm2. The main finding was the significant difference between mean ALOM area at the mid-vertebral body level and other three levels (p < 0.0001). The subsequent verification study showed the presence of vertebral segmental arteries at the mid-vertebral body level in nearly all images irrespective of the presence of DISH. A larger area of ALOM seemed associated with increased counter-clockwise rotation (away from the aorta) of the centroid relative to the anteroposterior axis. The results from the present study suggest a predisposition for fractures through the vertebral body and a role for the arterial system in the inhibition of soft tissue ossification