57 research outputs found
Neuobičanjeni nalaz devetopjegne drhtulje Torpedo torpedo (Linnaues, 1758) (Chondrichthyes: Torpedinidae), u vodama južne Francuske
A nine-ocellated Torpedo torpedo, caught off the Languedoc coast in southern France (northern Mediterranean) is described in this paper. This is the greatest number of ocellae recorded to date in this species.U ovom radu se opisuje primjerak drhtulje, Torpedo torpedo iz obalnih voda Laguedoc-a (južna Francuska, sjeverni Mediteran) koja je imala 9 pjega što je do sada za ovu vrstu najveći zabilježeni broj
0169 : Segregated calcium stores are important for stretch-induced calcium signaling in smooth muscle cells: Implication in pulmonary hypertension
Pulmonary arterial smooth muscle cells (PASMC) are submitted to stretch forces exerted by the blood pressure. They can transduce a mechanical stimulus of stretch into a biological response of contraction, a mechanism called myogenic tone which involves Ca2+ influx through stretch-activated channels (SAC). We investigate how the subcellular organization of Ca2+ stores in PASMC (sarcoplasmic reticulum (SR), lysosomes and mitochondria) is important for the Ca2+ response to stretch during PH.Studies were performed in freshly isolated PASMC from control rats and rats with a pulmonary hypertension induced by an injection of monocrotaline (MCT). Inward currents from SAC were recorded after a negative pressure applied by a patch-clamp pipette. Cytosolic Ca2+ was also measured with the fluo4 probe and mitochondrial Ca2+ with the rhod2 probe after an osmotic shock. A pharmacological approach coupled with different coimmunolabelings of ryanodine receptors (RyR) and SERCA2 pumps was used to investigate which RyR subtype is involved in Ca2+ response to stretch.PASMC exhibit segregated Ca2+ stores: a subplasmalemnal SR store with RyR1 and SERCA2b, associated to mitochondria and a perinuclear SR store with RyR3 and SERCA2a. We showed that a stretch of PASMC induces an inward Ca2+ influx through SAC that is amplified by a Ca2+ release by RyR1, which is buffered by mitochondria. In MCT rats, the subcellular organization of RyR subtypes is modified: RyR3 and SERCA2a are not only expressed in a perinuclear area but also in a subplasmalemnal level. This is correlated with a different organization of mitochondria. In MCT rats, this new organisation leads to a greater amplification by all RyR subtypes and to a higher Ca2+ increase induced by stretch. Furthermore, the Ca2+ response to stretch is enhanced by a mechanism independent on extracellular Ca2+, involving caveolae.The spatial organization of Ca2+ stores in PASMC is important for cell signaling and plays a causal role in PH
Crecimiento y reproducción de la dorada, Sparus aurata en la laguna de Mellah (nordeste de Argelia)
Gilthead seabream Sparus aurata (L.), a protandrous hermaphrodite, was caught in Mellah lagoon (Algeria) from July 1997 to June 1998. Its age, growth and reproduction were studied. Fish ranged in size from 157 to 610 mm total length and weighed from 60 to 4000 g wet weight. There were fish aged 1+ to 7+ years old in the samples. Direct scale readings were made by counting the number of rings. These were compared with the data obtained by backcalculating the lengths at different ages. These two methods were in agreement and showed that the growth rate of gilthead seabream in Mellah lagoon is very high compared to other study areas. The growth parameters of the Von Bertalanffy equation were: L∞ = 55.33 cm, K = 0.513, t0 = - 0.282, with F’ = 7.359. The fitted length-weight relationship was W = 1.292. 10-2 L3.06. The reproductive season extended from October to January, with a peak in December. Sex inversion occurred at a total length of 44 cm. Sexual maturity was reached at 32.6 cm total length.Se capturaron ejemplares de dorada, Sparus aurata (L.), una especie hermafrodita proterándrica, en la laguna de Mellah (Argelia) entre Julio de 1997 y Junio de 1998. Se estudiaron la edad, el crecimiento y la reproducción. La talla de los ejemplares estudiados osciló entre 157 y 610 mm de longitud total, pesando entre 60 y 4000 g (peso fresco). Ejemplares de edades comprendidas entre 1+ y 7+ años estuvieron presentes en las muestras. La lectura directa de algunas escamas mediante el conteo del número de anillos fue comparada con los datos obtenidos por retrocálculo de las tallas a distintas edades. Los resultados de los dos métodos fueron similares y mostraron que la tasa de crecimiento de la dorada en la laguna de Mellah es muy alta en comparación con otras áreas de estudio. Los parámetros de crecimiento de la ecuación de Von Bertalanffy fueron los siguientes: L• = 55.33 cm, K = 0.513, t0 = - 0.282, con F’ = 7.359. El ajuste de la relación talla – peso fue el siguiente: W = 1.292. 10-2 L3.06. La estación reproductiva estuvo comprendida entre Octubre y Enero, con un pico en Diciembre. La inversión de sexo tuvo lugar a una longitud total de 44 cm. La madurez sexual se alcanzó a una longitud total de 32.6 cm.
Biologija reprodukcije Rhizoprionodon acutus (Rüppell, 1837)(Chondrichthyes: Carcharhinidae)u obalnom području Senegala (istočni dio tropskog Atlantika)
The milk shark, Rhizoprionodon acutus (Rüppel, 1837), is the shark species most abundantly landed at fishing sites along the Senegalese coast in the eastern tropical Atlantic. Adult males and females were mainly captured from March to September. The smallest adult male was 840 mm total length (TL) and weighed 2650 g; all males above 950 mm TL were adult. The smallest adult female was 890 mm TL and 4800 g; all females above 1000 mm were adult. The largest male and female were 1215 mm and 1260 mm TL and 6700 g and 6830 g, respectively. There was a significant difference in the total mass vs. TL relationship between males and females. Parturition and mating occurred in May and June. Gestation lasted approximately one year. Females had an annual reproductive cycle although some reproduced in alternate years. The diameter and mass of the largest yolked oocytes ranged 20-23 mm (mean 21.2±0.9) and 4.1-5.6 g (mean 4.8±0.5). Both uteri were compartmentalized into chambers with a single embryo in each chamber. Size and mass at birth, based on term embryos and neonates, ranged 325-500 mm TL (mean 391.4±24.4) and 127-350 g (mean 220.7±37.9). A chemical balance of development based on mean dry mass of the largest yolked oocytes and term embryos was 23. Ovarian fecundity was slightly higher than uterine fecundity. There was a slight positive relationship between uterine fecundity and female TL, but not between ovarian fecundity and female TL. Litter sizes ranged from one to eight (mean 3.5±1.3) with males and females equally distributed. In free-swimming specimens, females significantly outnumbered males, especially among sub-adult and adult specimens.Morski pas, Rhizoprionodon acutus (Rüppel, 1837), je najviše rasprostranjen na ribarskim postajama duž senegalske obale istočnog dijela tropskog Atlantika. Odrasli mužjaci i ženke su pretežito lovljeni od ožujka do rujna. Ukupna duljina (TL) najmanjeg primjerka mužjaka iznosila je 840 mm, a težina 2650 g, dok su svi odrasli mužjaci bili duži od 950 mm TL. Najmanja odrasla ženka bila je duga 890 mm TL i teška 4800 g, a sve odrasle ženke bile su duže od 1000 mm. Najveći primjerak mužjaka bio je dug 1215 mm i težak 6700 g, a najveći primjerak ženke bio je 1260 mm dug i 6830 g težak. Ustanovljena je statistički značajna razlika između odnosa mase i ukupne duljine (TL) kod mužjaka i ženki. Parenje i porod se odvijaju u svibnju i lipnju. Trudnoća je trajala oko godinu dana. Ženke su imale godišnji reproduktivni ciklus iako su se neke razmnožavale u naizmjeničnim godinama. Promjer najveće oocite sa žumanjcem iznosio je 20-23 mm (prosjek 21.2±0.9), a težina je kolebala između 4.1-5.6 g (prosjek 4.8±0.5). Oba uterusa bila su podijeljena u komorice i u svakoj od komorica razvijao se po jedan embrij. Dužina i težina kod rođenja, mjerena na embrijima i novorođenim primjercima procijenjene su na 325-500 mm TL (prosjek 391.4±24.4) i 127-350 g (prosjek 220.7±37.9). Kemijska ravnoteža razvoja, temeljena na prosječnoj suhoj težini najvećih oocita sa žumanjcem i embrijima bliskog vremenskog razdoblja, bila je 23. Ovarijska plodnost bila je veća od uterine plodnosti. Ustanovljen je pozitivni odnos između uterine plodnosti i ukupne duljine ženki, ali takav odnos nije ustanovljen kod ovarijske plodnosti i ukupne duljine (TL). Veličine izlegnutih mladih kolebale su od 1 do 8 (prosjek 3.5±1.3) podjednako kod mužjaka i ženki.
Općenito je bilo više ženki nego mužjaka, naročito među slobodno plivajućim odraslim primjercima
Biološka zapažanja na mački mrkulji, Scyliorhinus stellaris (Linnaeus, 1758) (Chondrichthyes: Scyliorhinidae) u kaptivitetu
Observations conducted over two years on nursehounds, Scyliorhinus stellaris, in captivity provided data on the number of eggs laid per year, embryonic development, size at hatching, length growth following hatching, and estimated fecundity.Preko dvije godine su vršena opažanja na mački mrkulji Scyliorhinus stellaris u kaptivitetu. Dobiveni su podaci o godišnje izleglom broju jaja, embrionalnom razvoju, veličini kod leženja, rastu dužine nakon leženja i procjeni plodnosti
Growth and reproduction of the gilthead seabream <i>Sparus aurata</i> in Mellah lagoon (north-eastern Algeria)
Forte différenciation génétique de la daurade <i>Sparus aurata</i> (L., 1758) entre les deux rives de la Méditerranée occidentale
Redescription de Lappanella fasciata (Cocco, 1833)= Ctenolabrus iris Valenciennes, 1839 et diagnose du genre Lappanella Jordan, 1890 (T\ue9l\ue9ost\ue9ens Perciformes Labridae)
Volume: 36Start Page: 578End Page: 58
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