53 research outputs found
The first spontaneous spawning of red drum Sciaenops ocellatus L. in Europe: broodstock management and early larval stages
No full textThe present paper reports a research on reproductive parameters and larval rearing of red drum (Sciaenops ocellatus) maintained in captivity for the first time in Europe. Red drum juveniles were obtained from United States in the late 90s. In early January 2013, 40 in total male and female red drums ranging from 34 to 47 cm in length were held in a 25 m3 rectangular tank with a closed recirculating system with a water flow of 6000 L/h, located in Lesina (FG) fish farm (Southern Italy). Water temperature and salinity ranged between 21.0 and 28.8°C and from 25 to 27 g/L respectively. The fish were fed commercial feed pellet (46% protein) at 1.1% of body weight daily. Sexual maturation occurred during the natural breeding season of red drum. Approximately 43 spawns were recorded by the end of July and continuing to mid-September, with mean number of 66.5 millions of eggs collected overall on spawn period. Batch fecundity (3.325*106 ova per female) and relative fecundity (361.41 ova/g body weight) were calculated. Fertilisation rate was 30 to 80%. Larvae were hatched at a mean total length of 2.40±0.33 mm and showed a gradual increase in size of approximately 0.378 mm/day for the first 40 day after hatching (DAH). Cannibalism was observed as larger larvae preyed on smaller ones; to limit the phenomenon red drum population was selected for size at 35 DAH. Reliable information on fecundity and larval stage is essential for encouraging Sciaenops ocellatus farming also in Mediterranean countries
Increased by-catch rates in the Gulf of Taranto, Italy, in 20 years: A clue about sea turtle population trends?
No full textInformation on sea turtle population trends is fundamental to assess the population status and the effects of conservation measures, and is considered a priority for sea turtle conservation. To provide insights on trends at sea, we compared by-catch data from long-liners fishing in the Gulf of Taranto in 2 periods: 1978-1979 and 1998-2003. A total of 653 loggerhead sea turtles (Caretta caretta) were captured in 2679 fishing sets targeting swordfish and albacore tuna; catch rates were significantly higher in the second period, while average turtle size was smaller. Although possible effects of sampling techniques cannot be excluded, a negative trend in the number of turtles in the study area and period was unlikely. © 2012 Chelonian Research Foundation
Prioritizing bridges at flood risk: a large-scale index based on overtopping and traffic impact
No full textInfluence of season on the glycoconjugates surface of stallion ejaculated spermatozoa
No full textSeasonal changes have been observed in stallion sperm morphology. Since carbohydrates of sperm glycocalyx play a key role in the sperm-egg recognition and zona binding, the aim of this study was to evaluate the distribution of carbohydrates in stallion ejaculates collected in two different periods of the year using lectin histochemistry. Semen from two fertile trotters was collected in winter (January) and summer (July) (3 ejaculates for each time), diluted in Tyrode’s medium, fixed in 4% (w/v) neutral formalin, smeared on slides and incubated with appropriate dilutions of 12 lectins. The spermatozoa from winter ejaculates reacted with 1) MAL II, SNA, HPA, Con A, WGA and GSA II in the whole cell surface, 2) PNA, RCA120 and SBA in the acrosomal region, 3) GSA I-B4 in the entire head, 4) DBA and UEA I in the post-acrosomal region and tail. The spermatozoa contained in summer ejaculates did not show GSA I-B4 reactivity, whereas they displayed SBA affinity also in post-acrosomal region which was unreactive to UEA I. In addition, the tail of July collected spermatozoa did not contain binding sites for UEA I and GSA II. These results suggest that the expression of oligosaccharide sequences of stallion sperm glycocalyx is time-dependent and that the acrosomal region shows a more stable glycoconjugate pattern with respect to other regions. Lastly, carbohydrate pattern of the glycocalyx could be important in the assessment of semen quality in stallions
A Multi-Biomarker Approach in European Sea Bass Exposed to Dynamic Temperature Changes under Dietary Supplementation with Origanum vulgare Essential Oil
No full textA feeding trial for 150 days was carried out to evaluate the cross-effects between oregano essential oil (EO) dietary supplementation and dynamic temperature change in sea bass. Under exposure to rising temperature (13–25 °C), fish were fed with a control diet (CD) and two experimental diets supplemented with 100 (D100) and 200 ppm (D200) of EO. Feed inclusion of EO promoted the activity of antioxidant enzymes in sea bass exposed to increasing temperature. Consistently with the temperature rise, TBARS concentrations increased in CD and D200 groups, whereas were almost stable in D100. Trend of blood glucose in fish fed on CD was likely affected by glycogenolysis and gluconeogenesis. Similarly, the depletion of triglycerides and cholesterol in fish fed on CD likely supported the energy cost of gluconeogenesis. On the other hand, the reduction of glucose, triglycerides, and cholesterol in D100 and D200 was mainly attributable to the hypoglycemic and hypolipidemic effects of EO. The higher levels of serum protein observed in D100 and D200 groups were also associated to a reduced thermal stress compared to CD. EO dietary supplementation may be a promising strategy to alleviate the negative effects of temperature shift on sea bass physiological and oxidative state
Histological investigation on the ovarian cycle of the bluefin tuna in the western and central Mediterranean
No full textThe histological analysis of eastern Atlantic bluefin tuna Thunnus thynnus ovaries caught from February to September 1999-2000, made it possible to distinguish the presence of seven oocyte developmental stages and allowed the characterization of six time-dependent ovary maturity stages. The ovaries of mature (fork length, L F ≥ 110 cm) bluefin tuna were non-active from August (spent period) to March (quiescent period) when they contained only perinucleolarstage oocytes. Ovary development started in April to early May (recrudescent period) with the appearance of oocytes at the lipid stage. Vitellogenesis appeared in mid-May (ripening period) and post-vitellogenesis occurred in late May to mid-June (pre-spawning period). In late June to early July, hydrated oocytes, a sign of imminent spawning, were found only in specimens caught in Balearic waters. Females ranging between 100 and 110 cm L F, captured during the recrudescent and ripening periods, had the largest oocytes at the lipid stage, most of which were degenerating. An extensive vitellogenic atresia was observed in the ovaries of five females caught during the spawning period in non-spawning areas
Morphological and molecular changes in dromedary uterine glands during pregnancy
No full textThe uterine glands synthesize and secrete substances essential for the survival and development of the conceptus and associated extra-embryonic membranes. In dromedary, morphological and glyco-histochemical studies have been carried out on the feto-maternal interface but investigations regarding the glycoconjugates produced in the uterine glands during gestation are lacking. The aim of this study was to investigate the morphological and molecular changes of dromedary uterine glands during pregnancy. Uterus fragments from 3rd and 6th month pregnant dromedaries were fixed in 4% (w/v) neutral formalin and embedded in paraffin wax. Morphometric examinations were carried out on Haematoxyline-Eosin stained sections. Histochemical reactions were performed to evaluate the secretion of proteins with the bromophenol blue method and carbohydrates by means of PAS (neutral mucosubstances/glycoproteins), Alcian blue (AB) pH 2.5 (carboxylated mucosubstances) and AB pH 1.0 (sulphated mucosubstances). In addition, the analysis of oligosaccharides was performed with 5 lectins in association with sialidase (s) treatment.
Uterine glands from 6 month pregnant dromedary (6mp) were larger and the columnar epithelium was taller than 3 month pregnant (3mp) ones. Mean gland diameter was 60.0 ± 10.6 μm in 6mp and 47.8 ± 17.9 μm in 3mp (p<0.05); mean epithelium height was 16.2 ± 3.0 μm in 6mp and 13.8 ± 2.5 μm in 3mp (p< 0,05). 6mp contained dilated glands in the deep zone of the endometrium. The mean diameter of these glands was 104.7 ± 19.5 μm and the cuboidal lining epithelium was 9.7 ± 1.8 μm tall. Lumen glands from both 3mp and 6mp dromedaries contained glycoconjugates with terminal Galβ1,4GlcNAc (PNA) and with internal/terminal αMan (Con A affinity). The lumen of dilated glands of 6mp was full of proteins, neutral glycoconjugates, as well as glycans terminating with Neu5Acα2,6Gal/GalNAc, GalNAcα1,3GalNAcα1,3Galβ1,4Galβ1,4GlcNAc (SNA and DBA reactivity). The results of this study show that during gestation, in addition to morphological changes, variations also occur in the substances secreted from dromedary uterine glands and that the secretions mostly consist of proteins and neutral glycoconjugates, whereas acidic substances are scarcely secreted. As in other mammals, the morphology and molecules produced in the uterine glands during pregnancy show changes as pregnancy progresses. These findings are related to the morpho-functional effects of changes occurring in hormone secretion during gestation in the dromedary
Differential lectin binding patterns in the oviductal ampulla of the horse during oestrus
No full textWe investigated the oligosaccharide sequence of glycoconjugates,
mainly sialoglycoconjugates, in the horse oviductal
ampulla during oestrus by means of lectin and pre-lectin
methods such as the KOH-neuraminidase procedure to
remove sialic acid residues and incubation withN-glycosidase
F to cleaveN-linked glycans. Ciliated cells displayedN-linked
oligosaccharides throughout the cytoplasm. The cilia
glycocalyx expressed bothN- andO-linked (mucin-type)
oligosaccharides, both showing a high variety of terminal
sequences. In the most non-ciliated cells, the whole cytoplasm
containedN-linked oligosaccharides with terminal
αGal as well as mucin-type glycans with terminal Forssman
pentasaccharides. In a few scattered non-ciliated cells, the
whole cytoplasm displayed sialylatedN-linked oligosaccharides
with terminal Neu5Ac-GalNAc andO-linked glycans terminating
with neutral and/or αGalNAc, Neu5Acα2,6Gal/
GalNAc, Neu5AcGalβ1,3GalNAc. Supra-nuclear granules,
probably Golgi zones, of non-ciliated cells showed mainlyO-linked
glycans rich in sialic acid residues. The luminal surface
of non-ciliated cells showedN-linked oligosaccharides,
containing terminal/internal αMan/αGlc, βGlcNAc and terminal
αGal, as well as mucin-type oligosaccharides terminating
with a large variety of either neutral saccharides or
sialylated sequences. Apical protrusions containingO-linked
oligosaccharides with terminal Forssman pentasaccharide,
Neu5Ac-Galβ1,4GlcNAc, Neu5Ac-GalNAc were seen in nonciliated
cells scattered along the epithelium. These findings
show the presence of sialoglycoconjugates in the oviductal
ampulla epithelium of the mare and the existence of different
lectin binding profiles between ciliated and non-ciliated
(secretory) cells, as well as the presence of non-ciliated cell
sub-types which might determine functional differences
along the ampullary epithelium of mare oviduct
Distribution of sialoglycoconjugates in the oviductal isthmus of the horse during anoestrus, oestrus and pregnancy: a lectin histochemistry study
No full textThe distribution of sialic acid residues as well as other glycosidic
sugars has been investigated in the horse oviductal isthmus
during anoestrus, oestrus and pregnancy by means of
lectin and pre-lectin methods. Ciliated cells and non-ciliated
(secretory) cells exhibited different lectin binding profiles
that were found to change during the investigated stages.
Ciliated cells did not show any reactivity in the basal cytoplasm,
while the supra-nuclear cytoplasm displayed a few of
oligosaccharides with terminal and internal amannose (Man)
and/or aglucose (Glc) during oestrus and pregnancy and a
moderate presence of oligosaccharides terminating in afucose
(Fuc) during oestrus; cilia exhibited a more complex glycoconjugate
pattern for the presence of oligosaccharides terminating
in N-acetylgalactosamine (GalNAc), GalNAca1,3
GalNAca1,3galactose(Gal)b1,4Galb1,4N-acetylglucosamine(
GlcNAc), Fuc, sialic acid (Neu5Ac)-aGalNAc belonging
or not to the GalNAca1,3GalNAca1,3 Galb1,4 Galb1,
4GlcNAc sequence, and.aGalNAc and Neu5Aca 2,6Gal/GalNAc
increased during oestrus. Cilia displayed terminal Galb1,3
GalNAc in pregnancy, terminal aGal in anoestrus and pregnancy
and terminal or internal D-GlcNAc during anoestrus
and pregnancy, respectively. The whole cytoplasm of non-ciliated
cells showed oligosaccharides terminating with
aGalNAc, Neu5Aca2,6Gal/GalNAc, Neu5Ac GalNAca
1,3GalNAca1,3Galb1,4Galb1,4GlcNAc during the investigated
stages, as well as GlcNAc in anoestrus and pregnancy.
The supra-nuclear zone of non-ciliated cells exhibited
oligosaccharides with terminal Galb1,4GlcNAc and internal
Man during oestrus and pregnancy as well as terminal aGal
and Fuc in oestrus and Neu5Ac-Galb1,3GalNAc in pregnancy.
The luminal surface of non-ciliated cells showed glycans
terminating with aGalNAc and/or Neu5Ac GalNAca1,3
GalNAca1,3Galb1,4Galb1,4GlcNAc in all specimens, oligosaccharides
with terminal Galb1,4GlcNAc and internal Man during
oestrus and pregnancy, Neu5Ac a2,6Gal/GalNAc in
anoestrus and oestrus, and glycans terminating with
Galb1,3GalNAc, Neu5A aca2,3 Galb1, 4GlcNac, Neu5ac-
Galb1,3GalNAc, Neu5Ac-Galb1,4 GlcNAc in pregnancy.
These findings show the presence of sialoglycoconjugates in
the oviductal isthmus of the mare as well as the existence of
great modifications in the glycoconjugates linked to different
physiological conditions
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