Sex and reproductive stage differences in the growth, metabolism, feed, fecal production, excretion and energy budget of the Amazon River prawn (Macrobrachium amazonicum)

Abstract

The aim of this study was to evaluate differences in various physiological measures (growth, fecal production, feed intake, nitrogenous excretion, oxygen consumption, energy substrate used, and energy budget) among males, ovigerous females and non-ovigerous females of the freshwater prawn Macrobrachium amazonicum. This species exhibits pronounced sexual dimorphism and different male morphotypes and has the potential for use in aquaculture. Males and non-ovigerous females were studied for 30 days. Ovigerous females were studied for 10 days. Prawns were fed commercial prawn food, and all males were of the Translucent Claw (TC) morphotype. The results demonstrate physiological differences both between males and females and between females of different reproductive stages. Males had higher rates of ingestion, growth and oxygen consumption and less fecal loss than females. We postulate that in the absence of other morphotypes, TC males may exhibit increased growth rates. Males and females used protein as an energy substrate. Males channeled approximately 9% of their energy budget into growth, whereas non-ovigerous and ovigerous females channeled only 1.4 ± 0.4 and 0.07 ± 0.07%, respectively. Whereas males and non-ovigerous females channeled 9.0 ± 9.74 and 61.8 ± 3.0%, respectively, of the energy ingested into metabolism, ovigerous females channeled 97.7 ± 4.7% into metabolism, likely due to the frequent beating of their pleopods, which oxygenates and cleans the eggs. As reported for marine prawns, males and non-ovigerous females of M. amazonicum lost approximately 5% of their ingested energy in exuviae. The physiological differences observed between the sexes and between females of different reproductive stages might reflect corresponding differences in patterns of activity, growth, and reproduction.

Are there any physiological differences between the male morphotypes of the freshwater shrimp Macrobrachium amazonicum (Heller, 1862) (Caridea: Palaemonidae)?

“…These results suggest that the TC morphotype invests a great portion of the energy ingested in growth, as do the CC and GC1 morphotypes. The elevated growth rates observed in CC and GC1 (present work) and in TC (Augusto and Masui, 2014) are consistent because these morphotypes are smaller and are expected to require a significant investment in growth. GC1 males, however,…”

“…According to Moraes- Riodades and Valenti (2004), GC2 is the morphotype with the largest overall size and with the largest chelae, and is dominant in the population. Augusto and Masui (2014) verified that the TC morphotype gains approximately 15 mg WW −1 day −1 , which corresponds to a gain of 22% of its initial wet weight after 30 days. These results suggest that the TC morphotype invests a great portion of the energy ingested in growth, as do the CC and GC1 morphotypes.…”

“…We compared the physiological characteristics of three morphotypes (CC, GC1 and GC2) of M. amazonicum fed with commercial food by evaluating the metabolism, nitrogenous excretion, growth, energy substrate (proteins, carbohydrates or lipids) predominantly oxidized, ingestion, fecal production and energy expenditure from molting. These same physiological characteristics have already been described by Augusto and Masui (2014) for the TC morphotype and will be used for comparative purposes with the other morphotypes studied here.…”

“…Shrimp were kept for 24 h without food to avoid the calorigenic effect of food and their gut content was observed with the purpose of verifying the absence of food (Rosas et al, 1999;Lemos and Phan, 2001). After this period, animals were placed in individual conical respirometric chambers containing 440 ml of filtered water and maintained in trays with water and an electrical heater at Downloaded from https://academic.oup.com/jcb/article-abstract/36/5/716/2735728 by Universidade Estadual Paulista J�lio de Mesquita Filho user on 07 May 2019 30°C (Augusto and Masui, 2014). Individuals were kept in respirometric chambers for 30 min with aeration to acclimatize them and reduce the stress caused by manipulation.…”

Estudo bioquímico comparativo da (Na+ , K+)-ATPase branquial de Macrobrachium amazonicum (Heller, 1862) habitante de regiões continentais

“…Os machos de M. amazonicum apresentam quatros morfotipos, que se diferem quanto às características morfológicas, com destaque ao tamanho dos quelípides e à coloração (Moraes-Riodades & Valenti, 2004;Santos et al, 2006). Além das diferenças morfológicas, os diferentes grupos também apresentam diferenças fisiológicas entre si (Augusto & Masui, 2014;Augusto & Valenti, 2016).…”