Stunting-Induced Compensatory Growth in Aquaculture: Mechanisms and Implications | Book Publisher International

Compensatory growth (CG) is an elevated growth rate often observed in fish that have previously experienced stress and returned to normal conditions. To induce CG responses, fish must undergo a catabolic phase, where they utilize endogenous energy reserves. In nature, fish encounter catabolic phases due to food limitations, migration and predation. In aquaculture, the catabolic phase is achieved through stunting practices such as feed restrictions, environmental manipulation and crowding stress. When fish experience the catabolic phase in captivity, they undergo various behavioural, physiological and biochemical changes to cope with the altered environmental conditions. Behavioural changes include reduced swimming and locomotion activities. Physiological adjustments involve metabolic changes such as reduced circulation of proteins, antibodies, enzymes and other molecular compounds. In biochemical alterations, fish utilize endogenous energy resources, such as lipids and proteins, which affect their overall nutritional composition. However, when stressed fish return to favourable conditions, they exhibit a CG response and rapidly restore their lost body weight, metabolic compounds and endogenous energy reserves. The effectiveness of the CG response can vary significantly depending on several factors, including the specific fish species, duration and severity of the stunting practice, as well as the conditions during the refeeding phase. This phenomenon has been harnessed in aquaculture to produce stunted fish seed. Extensive research on CG responses in fish over the past few decades has yielded inconsistent results, fostering debate over the practical application of CG response in aquaculture. To better understand and potentially leverage this phenomenon in aquaculture practices, it is crucial to critically examine the physiological changes that occur in fish during both stunting and post-stunting phases. This book aims to provide a comprehensive analysis of the actual changes occurring in fish during the stunting and post-stunting phases and explore the potential applications of CG responses in aquaculture, offering insights for more efficient and sustainable fish farming practices.

 

Author (s) Details

Suresh Babu Padinhate Purayil
ICAR-Central Marine Fisheries Research Institute, Kochi, Kerala, India.

 

Ande P. Muralidhar
ICAR-Central Institute of Fisheries Education, Versova, Mumbai, Maharashtra, India.

 

Karthireddy Syamala
ICAR-Central Institute of Fisheries Education, Versova, Mumbai, Maharashtra, India.

 

Somu Sunder Lingam R
Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Nagapattinam, Tamil Nadu, India.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/mono/978-93-49473-12-6

Dietary Supplementation with Seaweed Extracts: Impact on Growth, Hematology, and Physiology of Nile Tilapia, Oreochromis niloticus | Chapter 7 | Research Advances and Challenges in Agricultural Sciences Vol. 6

The utilization of phytochemically enriched diets, particularly those supplemented with seaweed extracts, has gained attention in aquaculture for enhancing fish growth and health. This study was conducted to determine the haemato-physiological response of Nile Tilapia (Oreochromis niloticus, Linnaeus 1758) fed with phytochemically enriched formulated diets. This was carried out for 90 culture days using four treatments where three out of four were seaweed-supplemented diets (Kappaphycus alvarezii, Ulva lactuta, Sargassum muticum). Treatments were distributed with the following: Treatment I (Control), Treatment II (K. alvarezii), Treatment III (U. lactuta), and Treatment IV (S. muticum). In the growth performance, Treatment I reached the highest mean weight and length while lowest in Treatment IV. The highest mean weight and length gain was also achieved by Treatment I and lowest in Treatment IV. Survival rate was found highest in Treatment II and lowest in Treatment IV. In the case of GSI and HSI, Treatment I achieved the highest values while lowest in Treatment IV. The maximum SSI value was achieved by Treatment III while it was least achieved by Treatment IV. In relation to condition factor, Treatment IV classified as fair fish, while the rest of the Treatments attained the excellent condition. In the gonadal development, 27.27% are at Stage I (Immature) while 38.64% are at Stage II (Maturing I), 20.45% Stage III (Maturing II) and 13.64% reached the Stage IV (Mature). With regards to the haematological response, Treatment III had the highest count of White Blood Cells while lowest in Treatment II. In Red Blood Cells, hemoglobin was least counted in Treatment IV, while hematocrit found least in Treatment I. Treatment I had the highest count of platelet while lowest in Treatment IV. The physico-chemical parameters of water such as temperature and pH fell within the tolerable limits for O. niloticus culture. The result of the study shows that seaweed extract-supplemented diets has no significant effect to the growth of fish within 90 days culture period. Thus, it is highly recommended to use a higher dosage of the same species of seaweed and/or use other species.

Author(s) Details:

Jaynos R. Cortes,
College of Forestry, Agriculture, and Aquatic Sciences, North Eastern Mindanao State University – Lianga Campus, Lianga, Surigao del Sur, Philippines and Center of Research for Aquamarine Life Sustainability (CoRALS), North Eastern Mindanao State University– Lianga Campus, Lianga, Surigao del Sur, Philippines.

John Arman P. Tenio,
College of Forestry, Agriculture, and Aquatic Sciences, North Eastern Mindanao State University – Lianga Campus, Lianga, Surigao del Sur, Philippines.

Heldiegardis B. Amista,
College of Forestry, Agriculture, and Aquatic Sciences, North Eastern Mindanao State University – Lianga Campus, Lianga, Surigao del Sur, Philippines.

Jonamie C. Cortes,
College of Forestry, Agriculture, and Aquatic Sciences, North Eastern Mindanao State University – Lianga Campus, Lianga, Surigao del Sur, Philippines.

Limuel N. Idjao,
College of Forestry, Agriculture, and Aquatic Sciences, North Eastern Mindanao State University – Lianga Campus, Lianga, Surigao del Sur, Philippines.

Please see the link here: https://stm.bookpi.org/RACAS-V6/article/view/14202