Development and functional morphology of the foreguts of larvae and postlarvae of three crustacean decapods

Abstract

The development of the foregut structure and the digestive function of the decapods Litopenaeus vannamei, Sesarma rectum and Callichirus major larvae and post larvae were examined. The protozoeal foregut of L. vannamei is simple, lacking a cardiopyloric valve and bearing a rudimentary filter press. In mysis, the filter press is more developed. In the juvenile stage, grooves and a small lateral tooth arise. In S. rectum, the foregut has a functional cardiopyloric valve and a filter press. The megalopal and juvenile stages of this species have a gastric mill similar to those in adult crabs. In C. major, the foregut of the zoeae is specialized, with the appearance of some rigid structures, but no gastric mill was found. Calcified structures are observed in the megalopae and they become more developed in the juvenile stage. The results support suppositions, previously reported in other studies, that feeding behavior of each larval and postlarval stage is directly related to the morphological characteristics of the foreguts.Keywords: foregut, Litopenaeus vannamei, Sesarma rectum, Callichirus major, morphology. Desenvolvimento e morfologia funcional dos estômagos de larvas e pós-larvas de três crustáceos decápodesResumo O desenvolvimento da estrutura do estômago e da função digestiva foi examinada em larvas e pós-larvas de Litopenaeus vannamei, Sesarma rectum e Callichirus major. O estômago do protozoea de L. vannamei é muito simples, sem válvu-la cárdiopilórica e apresenta um filtro pilórico rudimentar. Em mysis, o filtro pilórico parece ser mais desenvolvido. No juvenil I surgem calhas e dentes laterais pouco desenvolvidos. Os estômagos dos zoeae de S. rectum possuem a válvula cárdiopilórica e o filtro pilórico funcionais. Nos estágios megalopa e juvenil I o moinho gástrico é complexo. Em C. major, os estômagos dos zoeae se mostram especializados exibindo algumas estruturas rígidas, mas não apresentam moinho gástrico. Esta estrutura surge no megalopa e juvenil I. Os resultados suportam suposições anteriores que o comportamento alimentar de larvas e pós-larvas está diretamente relacionado com as características morfológicas dos estômagos.

Development and functional morphology of the larval foregut of two brachyuran species from Northern Brazil

“…However, these larvae are able to feed on soft food particles, such as Artemia nauplii, rotifers, microalgae and other zooplanktonic species available in the aquatic environment. Similarities with the morphological features of the zoea I foregut of decapods were also observed in several other species (Factor 1982, 1989, Nishida et al 1990, Abrunhosa and Kittaka 1997a, b, Abrunhosa and Melo 2002, 2008, Abrunhosa et al 2003). However, some first larvae of the callianissid Lepidophthalmus siriboia have been reported showing only few minute setae in the cardiac and pyloric chambers, as well as a reduced filter press ).…”

Osmoregulation pattern and salinity tolerance of the white shrimp Litopenaeus vannamei (Boone, 1931) during post-embryonic development

“…This result suggests that Mysis stages most probably require certain salinity level for an optimal development. During this stage, dramatic morphological changes occur, which mark the transition between herbivore to carnivore feeding behavior (Abrunhosa and Melo, 2008). It will be necessary to study larval development under different salinities to corroborate this hypothesis, as good tolerance is not equivalent to good development.…”

“…The effect of starvation under osmotic stress has been demonstrated in PL20: the magnitude of survival is low in unfed organisms (Palacios et al, 2004). Also, during these stages occur the development of other major systems such as the digestive system (Abrunhosa and Melo, 2008) and the reproductive organs (Garza-Torres et al, 2009), in parallel with the development of osmoregulatory organs that implies an energy expenditure.…”

Foregut morphology of Macrobrachium carcinus (Crustacea, Decapoda, Palaemonidae)

“…There is much information about the decapod digestive tract, particularly concerning to economically important species, such as palinurids, scyllarids and penaeids (Cox and Bruce 2003;Suthers and Anderson 2006;Abrunhosa and Melo 2008). Little information on the mouthparts or alimentary tract of the genus Macrobrachium Bate 1868 and other caridean prawns has been reported in the literature, as an example larvae of M. rosenbergii De Man, 1879 (Abrunhosa and Melo 2002) and M. amazonicum (Heller, 1862) (Queiroz et al 2011) and adults of M. malcolmsonii (Milne Edwards, 1844) (Patwardhan 1935a), M. acanthurus (Wiegmann, 1836) (Felgenhauer and Abele 1989) and M. carcinus (Lima et al 2014).…”