An immunohistochemical study
of structure and development of the nervous system in the brine shrimp
Artemia salina Linnaeus, 1758 (Branchiopoda, Anostraca) with remarks on the
evolution of the arthropod brain
S.
Harzsch, J. Glotzner-2002
Arthporod Structure and Development, 30(4): 251-270
(from Current Contents)
Abstract:
Brain morphology is an important character in the
discussion of arthropod relationships. While a large body of literature is
available on the brains of Hexapoda and Malacostraca, the structure of the
brain has been rarely studied in representatives of the Entomostraca. This
account examines the morphology and development of the nervous system in the
brine shrimp Artemia salina Linnaeus, 1758 (Crustacea, Branchiopoda,
Anostraca) by classical histology arid immunohistochemistry against synaptic
proteins (synapsins), and the neurotransmitters serotonin and histamine. The
results indicate that the shape of the developing larval brain in A. salina
(a circurnstomodeal ring of neuropil) closely resembles that in
malacostracan embryos. Furthermore, the organization of the central complex
as well as the tritocerebral innervation pattern of the labrum is homologous
in this species and in Malacostraca. Nevertheless, differences exist in the
layout of the deutocerebrum, specifically in the absence of olfactory
glomeruli in A. salina while the glomerular organization of the olfactory
lobe is a character in the ground pattern of Malacostraca. These findings
are compared to the brain structure in other Euarthropoda and possible
phylogenetic implications are discussed.
(Univ Ulm; Sekt Biosyst Dokumentat; Helmholtzstr 20;
D-89081 Ulm; Germany, e-mail: steffen.harzsch@biologie.uni-ulm.de)