Journal of Aquaculture & Marine Biology Research Article Open Access Comparative study of the gut contents of penaeus japonicus bate 1888 (decapoda: penaeidae) in semi-intensive culture and in brackish water wild environment Abstract Volume 4 Issue 6 - 2016 The trophic adaptability of a species may influence its dispersion potential and the ability 1 2 3 to invade foreign territories. Understanding the factors that facilitate trophic adaptability V Zupo, F Lumare, V Bisignano 1Stazione Zoologica Anton Dohrn IME Department, Benthic may help the provision of forecasts about the potential dispersion of allocthonous species, Ecology Center, Italy even in a warmer and acidified world, according to the current trends of global changes. 2Dipartimento di Biologia, Universit Various studies demonstrated the adaptability of Penaeus japonicus Bate to variable feeding 3CNRInstitute of Biosciences and Bioresources, National regimes under natural conditions. To optimize artificial diets for the aquaculture of Penaeid Research Council, Italy shrimps, gut content data of specimens cultured in ponds were compared to contents from shrimps fed on natural macro benthic communities in a brackish-water lagoon. In addition, Correspondence: V Zupo, Stazione Zoologica Anton Dohrn the feeding adaptability of this shrimp to scarcely diversified benthic associations was IME Department, Benthic Ecology Center, Italy, tested in aquaculture ponds. Our comparative analyses confirm that P. japonicus feeding Email pattern may be largely adapted to variations in the available benthic organisms, in different management conditions. Received: November 18, 2016 | Published: December 15, 2016 Keywords: Penaeus japonicus, Food, Brackish water, Culture, Adaptability, Marsupenaeus japonicus Introduction Zenetos.13 it was considered as a Lessepsian migrant in the Mediter- ranean waters since 1924. Obviously, its successful adaptation in the Penaeus japonicusBate 1888, the “Kuruma shrimp”, whose ta- Mediterranean may threaten indigenous species, as P. keraturus and 1 xonomical identity is still debated Tsoi et al. is an ideal species for other crustacean decapods, as well as its main prey, represented by aquaculture purposes, due to its adaptability to different environmen- molluscs and polychaetes.15 tal conditions Lumare.2 The species is still indicated by means od two scientific names, i.e., P. japonicus and Marsupenaeus japonicus, due A dynamic feeding model was demonstrated for this species in to a controversy in the status of the genus Penaeus Fabricius, 1798 relationship to the predation on natural benthic populations.16 This (see, for example, Pérez Farfante & Kensley Ma et al.3,4 Both names evidence allows us for predicting a destructive influence of P. japoni- are still used by various organizations and databases, eg. WoRMS cus on wild ecosystems as well as a certain degree of adaptability to (World Register Marine Species), FAO, DAISIE (Delivering Alien In- benthic communities characterized by low species diversity, as those vasive Species Inventories for Europe);however, in this study we will characterizing the culture ponds. Therefore a study comparing natural follow the most updated results Tsoi et al.1 for the definition of Pe- feeding patterns with those observed in prawns managed in exten- naeus and hence we will use the current name Penaeus japonicus Bate sive and semi-intensive conditions was performed by means of gut 1888. contents analyses. The results of the present study, in fact, may allow from one side an optimization of inexpensive diets for this species Penaeus japonicus exhibits attractive brownish-red bands and it in aquaculture ponds and, on the other side, to explain some of the is named “the kuruma shrimp” because of a characteristic wheel-like factors promoting the adaptability of a given species when introduced banding pattern. It is economically important for the world shrimp in new areas. market due to an easy management of pond cultures and the fast grow- -out.5 Many aspects of its physiology and reproductive biology have Materials and methods been clarified.6,7 but the available information on its trophic needs in intensive and semi-extensive culture conditions is still incomplete. Five ponds were set in Cammarata (Lesina, Southern Italy) (Figure Previous studies identified the feeding patterns of P. japonicus under 1). The first 4 ponds (100 m2 each one) were managed in semi-exten- natural conditions, after its introduction in coastal lagoons.8-11 In fact, sive conditions, at density of 2.5; 1.5; 2.5; 1.5 post larvae (PL22) per this species appears to be able to easily invade new territories when square meter, respectively; the fifth one (200 m2) was managed in accidentally introduced in natural environments.12-13 and the global extensive conditions, at a density of 12 post-larvae (PL22) per square increase of temperatures in natural basins, even in the Mediterranean meter. 14 area, facilitates its dispersion. Water was partially changed daily, by pumping from the adjacent At present, Penaeus japonicus is widely distributed in Japan, the lagoon, in order to promote correct environmental conditions for the 17 South China Sea, Korea, the Archipelago of Malay, the Red Sea, the grow-out of the shrimps. and the development of benthic fauna and northern coast of Queensland in Australia, and the western Indian flora driven by larvae and various organisms present in the lagoon. Ocean, up to the eastern South Africa.3 However, according to Galil & The finest rate of changes was determined by measuring selected Submit Manuscript | http://medcraveonline.com J Aquac Mar Biol. 2016;4(6):14‒12. 1 ©2016 Zupo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestrited use, distribution, and build upon your work non-commercially. Comparative study of the gut contents of penaeus japonicus bate 1888 (decapoda: penaeidae) in semi- Copyright: 2 intensive culture and in brackish water wild environment ©2016 Zupo et al. chemical and physical parameters, i.e., temperature, salinity, pH, dis- Previous authors (Piscitelli & amp;Scalera Liaci, 1983) classified solved oxygen, dissolved nutrients. In particular, changes were per- each prey, on the basis of their frequency index (Fp), in the following formed to assure consistence of the above-mentioned parameters in categories: comparison to the natural ones, measured in the lagoon.18 To perform a. Fp> 50%: preferential prey, defining the feeding pattern of the the gut content analyses, three collections of shrimp were obtained species. in the early night from each pond, to obtain individuals containing undigested prey. The first sample refers to shrimps aged 6 weeks, the b. 10%>Fp>50%: secondary prey, representing a diet integration. second one refers to shrimps aged 12 weeks, and the last one refers to adults sampled a few days before the end of the experiment. c. Fp<10%: occasional prey, having little importance in the diet. In order to obtain quantitative information about the trophic needs of shrimp of different ages, the feeding index “FI” .19 was also calcula- ted; it is computed on the basis of the following relationship: 4. FI=(PCS / PTA) x 100, where PCS = weight of the gut contents. PTA = weight of the animal body. Results The average total length of individuals sampled in all ponds, in the three samples were, respectively 9.4, 13.4 and 15.0 cm (Table 1). The analysis of the gut contents, classified according to larger food cate- gories (Table 2) permits a direct comparison with the data obtained in brackish water wild environments.11 The preferential food items in all samples were Annelid Polychaetes (Fn=16.7%), insect larvae (Fn=12.7; represented mainly by Chironomid Dypters), Molluscs (Fn=15.3), and Crustaceans (Fn=19.9; represented mainly by Am- phipods and Copepods). Large amounts of artificial food (Fn=12.4) were found in prawns cultured in semi intensive conditions. Other Figure 1 Pond location in “Cammarata”, near the Lesina Lagoon. food items, less important, were macroalgae (Fn=14.0), Foraminife- Samples were immediately transferred in the laboratory and de- rids (Fn=1.3) and Isopod Crustaceans (Fn=1.3). ep-frozen. Each specimen was measured (total length), weighed, Table 1 Main biometric and trophic parameters of the three samples inves- and finally sacrificed, fixed and dissected for the analysis of the gut tigated contents. A presence-absence matrix was compiled, taking into ac- count each specimen sampled and each food item identified in its Sample 1 Sample 2 Sample 3 stomach, according to Zupo et al.2 Data were managed by means of Mean length 9.39 13.42 15.05 a MS-Excel spreadsheet and compared with those obtained by pre- Mean weight 5.72 15.72 25.19 vious authors.9,11,16 using Graph pad Prism software. In particular, the Gut weight 0.05 0.13 0.16 following indices were taken into account: Cv 13.3 12.5 25.9 FI 0.55 0.18 0.08 Numeric frequency, obtained on the basis of the following rela- tionship The comparison of the numeric frequencies of the main taxa fou- nd in the gut contents of individuals sampled in culture ponds (pre- 1. Fn= (Npi/Tp) x 100, where sent study) and in natural environments Piscitelli & Scalera Liaci.9 Np= number of individuals of the food item “i” demonstrated that the trophic importance of some taxa changed dra- matically under different environmental conditions, according to the Tp= Total number of individuals, of all food items, found in the age of prawns. In particular, insects and polychaetes were clearly pre- gut. valent food items in culture conditions, while a higher variability in prey taxa was observed in natural conditions. Molluscs (mainly bival- Prey frequency, obtained on the basis of the following relationship ves) were a preferential prey in both natural and culture conditions. 2. Fp= (Nspi/Ns) x 100, where A few taxa were found in the guts of individuals collected in pond algae were represented by four species, i.e., Blidingia sp, Cladopho- Nsp= number of guts containing the item “i” ra sp, Chaetomorpha gracilis and C.