1,354,202 research outputs found
Biochemical composition of a meso-bathyal lobster (Polycheles typhlops, Heller 1862 Decapoda, Palinura, Polychelidae)
No full textTo characterize some traits of the life strategies of Polycheles typhlops, a deep-sea small lobster
usually encountered as by-catch within deep trawls in the Southern Tyrrhenian Sea (Mediterranean
Sea), we analysed the biochemical composition of caudal muscles of 49 specimens collected in
March and April 2007. Differences in the biochemical composition between females and males
were weak, and relevant differences in protein (>90% of the organic C) and lipid (4-6%) contents
were observed between developmental stages both in females and males. These differences were
likely related to different food items and/or to the metabolic shifts associated with the reproduction.
We argue that this deep-sea lobster could cover a relevant role in the meso-pelagic food webs and
attract future commercial interests
Biochemical composition of a meso-bathyal lobster (Polycheles typhlops, Heller 1862 Decapoda, Palinura, Polychelidae)
No full textTo characterise some traits of the life strategies of Polycheles typhlops, a deep-sea small lobster usually encountered as by-catch within deep trawls in the Southern Tyrrhenian Sea (Mediterranean Sea), we analysed the biochemical composition of the caudal muscles of 49 specimens collected in March and April 2007. Differences in the biochemical composition between females and males were weak, but relevant differences in protein (>90% of the organic C) and lipid (4-6%) contents were observed between developmental stages both in females and males. These differences are likely to be related to different food items and/or to the metabolic shifts associated with their reproduction. We argue that this deep-sea lobster could cover a relevant role in the meso-pelagic food webs and attract future commercial interest
Trophic habits of the blackbelly rockfish, Helicolenus dactylopterus (Osteichthyes, Scorpaeniformes) in the Sardinian Channel
No full textRisultati preliminari sulle associazioni demersali nel canyon di Spartivento (Sardegna meridionale) = Preliminary data on demersal assemblages in Spartivento Canyon (South Sardinia)
No full textTrophic interactions among three rajids, Raja asterias, Raja brachyura and Raja miraletus
No full textOn the reproductive biology of the deep-sea lobster, Polycheles typhlops (Decapoda, Palinura, Polychelidae), from the central-western Mediterranean
No full textData are provided related to the reproductive biology of a deep-sea lobster, Polycheles typhlops, caught in Sardinian waters between 400 and 1400 m depth. Analyses were performed on 1180 females and 935 males. In both sexes, the carapace length decreased markedly and regularly with increasing depth; the females proved to be prevalent at greater bathymetric depths. The temporal evolution of the gonadosomatic index, and of the percentage distribution of the various stages of ovarian development, did not reveal any clear seasonality in reproduction for the species
Trophic habits of the Blackbelly rockfish, Helicolenus dactylopterus (Osteichthyes, Scorpaeniformes) in the Sardinian Channel = Alimentazione dello scorfano di fondale, Helicolenus dactylopterus (Osteichthyes, Scorpaeniformes) nel Canale di Sardegna
No full textFeeding habits of Helicolenus dactylopterus in the Sardinian waters were analysed. The tropic spectrum of this commercial species was mainly composed of crustaceans: Decapoda Natantia, Isopoda and Decapoda Brachyura. The diet changed according to the depth distribution and the size of the specimens
Feeding habits of the Blackbelly rockfish, Helicolenus dactylopterus (Osteichthyes, Scorpaeniformes) in the Sardinian Channel.
No full textOn the reproduction of Acanthephyra eximia s. I. Smith, 1884 in the central western Mediterranean
No full textMacroscopic and histological analysis were performed on the female gonads of Acanthephyra eximia. The macroscopic observation
regarding the changes of the ovaries leads us to identify six stages of development, validated by histological analysis
The reproductive cycle of a deep-sea eel, Nettastoma melanurum (Nettastomatidae: Anguilliformes) from the south-eastern Sardinian Sea (central-western Mediterranean)
No full textThe reproductive cycle of the deep-sea eel Nettastoma melanurum was described based on 397 specimens (171 males and 226 females). Experimental trawl surveys between depths of 772 and 1598 m and commercial hauls (580-600 m) on compact mud bottoms off the south-eastern Sardinian waters (central-western Mediterranean) were carried out. The Sardinian catches did not indicate any particular trend of size-range in relation to depth in both sexes and seem to be sexually dimorphic with females growing almost 9A cm longer than males at maximum lengths. It was a dioeceous and an oviparous deep-sea species. For females and males, six stages of oocyte development, characterizing the different stages of maturity, were identified. Histological examination demonstrated that ovaries of N. melanurum showed a 'group-synchronous' pattern, highlighting a type of monocyclic ovary. The species showed a size at first maturity of 53.5 cm and 50.5 cm total length in females and males respectively. The reproductive period appeared to be unique and well defined in both sexes. Their monthly changes of gonadosomatic index and maturation phases of ovaries and testis showed that the species was in a resting period from March to July. Vitellogenesis and spawning began in September and ended in January. Nettastoma melanurum seemed to be a fecund species (8132-18755 eggs)The reproductive cycle of the deep-sea eel Nettastoma melanurum was described based on 397 specimens (171 males and 226 females). Experimental trawl surveys between depths of 772 and 1598 m and commercial hauls (580-600 m) on compact mud bottoms off the south-eastern Sardinian waters (central-western Mediterranean) were carried out. The Sardinian catches did not indicate any particular trend of size-range in relation to depth in both sexes and seem to be sexually dimorphic with females growing almost 9A cm longer than males at maximum lengths. It was a dioeceous and an oviparous deep-sea species. For females and males, six stages of oocyte development, characterizing the different stages of maturity, were identified. Histological examination demonstrated that ovaries of N. melanurum showed a 'group-synchronous' pattern, highlighting a type of monocyclic ovary. The species showed a size at first maturity of 53.5 cm and 50.5 cm total length in females and males respectively. The reproductive period appeared to be unique and well defined in both sexes. Their monthly changes of gonadosomatic index and maturation phases of ovaries and testis showed that the species was in a resting period from March to July. Vitellogenesis and spawning began in September and ended in January. Nettastoma melanurum seemed to be a fecund species (8132-18755 eggs)
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