Growth, gonadal histology and liver lipid composition in Pagellus acarne

Transcription

1 Growth, gonadal hislogy and liver lipid composition Pagellus acarne Greco S., Genovese L., Micale V. Mare aquaculture ffish species diversification Zaragoza : CIHEAM Cahiers Options Méditerranéennes; n pages Article available on le / Article disponible en ligne à l adresse : To cite this article / Pour citer cet article Greco S., Genovese L., Micale V. Growth, gonadal hislogy and liver lipid composition Pagellus acarne. Mare aquaculture ffish species diversification. Zaragoza : CIHEAM, p (Cahiers Options Méditerranéennes; n. 16)

2 Growth, gonadal hislogy and liver lipid composition Pagellus acarne S. GRECO L. GENOVESE V. MICALE ISTITUTO SPERIMENTALE TALASSOGRAFICO CONSIGLIO NAZIONALE DELLE RICERCHE SPIANATA SAN RAINER MESSINA ITALY - and fat densities, at lowest density showed an weight of 220 days, with 8.5. Sce this species is gonads. A of the biochemical analysis of of a fish words: acarne, gonads, fatty acids, digestive enzymes. - La le à à l élevage de de population ont été testées. Les poissons matenus à la densité la 220 avec un qi l est passé de 4.7 à de cette espèce, le développement sexuel des gonades a été aussi étudié dans les conditions d élevage et mis en les la fiaction on acarne, 89

3 acarne is one of the Esso (1826). The of this by 250 mm long specimen caught by on. by, by the basi ctenidiali, be used as The species is and England caught fish out on stations but constant is fish 198 1) and is is one of the most on the out on acarne as this of on the the good it has it is known its those of the *th studied at the of the that has best exploitment of the seasonal changes of gonads, the lipid content of the on these specimens evaluate the with two pelletted one given 5% of body weight, and a one made of fish offal, given 25% of body weight= at a density of 8 this the 90

4 weight= 11.O5 1.5 g, mean size = 6.3 O 0.7 mm) and 40 this 5 Ym and staed with plastified The gonosomatic dex was calculated as gonadal weight X 100/ tal body weight. et al., this 10% AgN03 The effect of two ; each sample. on the digestive enzymes of obta the mm ( a 6000 O mutes ) activities. Growth Examg fiequency classes (Fig. 1) of lot F one can see that 38% 100 g, while 62% went beyond this. Of this 68% lot this,only a the an the lot of lowest density (lot A) which passes fiom a mean weight of 11.05k0.89 g. a fal two lots, at k2.38 and k2.35 g, of weight classes a substantial homogeneity can be the development of lot A, with 91

5 phenomenon of lot % of lot falls with. at double density, a few weight classes below the mean value at 220 days with a lot C this low weights weights of 120 and 130 g, test. an of ( yg-dl a maximum of pdl side the tank). 120 O 60 Lot F 43.6 f k f4.0 Lot 68.1f f Table 1 : of O 220 Lot A 86.24f1.93 Lot k Lot c 54.38k k0.89 Table 2 : of 220 days.

6 Fat metabolism is of the hepatic fatty acids of the lots of 3. acme. Lot acid Fatty A c Tot.sat k k k2.5 Tot. mono k k4.2 Tot. poly k k k k k the lots showed no A and Lot the ás. lot C, on the poly- 0-3 The study of the digestive capacity of showed ( Fig. 2a-2b ) elastase content of fish fed on fish fed on pellets; with ( Alliot it is The digestive capability of is always food, fact, may be volved fish, of is difficult. of gonads males. functional all

7 C-. C found Seasonal changes of the gonads All fish had bisexual gonads (ovo-testes) conta the most advanced gamegenic stages. Thus, the size of of of the functional sex of the dividual. The seasonal changes fish of Table 4, 5 and 6, A at fish at the at stage oocytes. that of the fish as by of by active than and C. As dicated by males, so that by some dividuals all the June and July, while it C the at the end of spawng, as shown by C kept on is some of the C is the high 6). by oogenesis, so that both and C and vitellogenic oocytes up

8 On fis?dm2 is advisable yield the best exploitation of fact, F. 1826) 28 (5), Ash feedg $&, & J.G. L. Sigma Tech. Bull., NO25 1, Sigma and ß. N.Y., pp C.V. 220,l-20. vol 22, no. 2, Fase Chem.,226:

9 Q) E.I m \ C I ? I F J- 5 II? 96

10 m ( + V X,: + No( P H l - $!- + + r m Q) h 97

11 i?

12 Lot. Lot. % M 10 O Fig. 1. Frequency hisgram of body weightdistribution thetwogroups of P. acarne. 99

13 Lot F 44,51% Lipase 55,49% 45,18% Amylase 19,56% 48,!36% Elastase 38,33% 12,71% Inteste KI Smach Caeca Fig. 2a. Distribution of the enzymatic activities relation diets. 1

14 Lot P 45,05% Lipase 54,95% I Inteste B Smach H Caeca 5 Fig. 2b. Distribution of the enzymatic activities relation diets. 1 o1