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Histological studies on the marsupium of two terrestrial isopods (Crustacea, Isopoda, Oniscidea).

Csonka D, Halasy K, Hornung E - Zookeys (2015)

Bottom Line: The quantitative analysis of the oostegites' cuticle proved that the outer part is about 2.5 - 3 times thicker compared to the inner part in both species.Cellular elements and moderately electron dense fleecy precipitate are found in the hemolymph space between the two cuticles of oostegites.We conclude that - besides the differences in marsupial shapes - the fine structure of the oostegites and cotyledons is hardly affected by the eco-morphological type, specifically the conglobating or non-conglobating character of the studied species.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Biology, Faculty of Veterinary Science, Szent István University, Rottenbiller str. 50, H-1077 Budapest, Hungary.

ABSTRACT
The marsupium, a brood pouch in peracarid crustaceans (Crustacea, Malacostraca) has evolved in terrestrial environment for providing nutrition and optimal conditions for embryogenesis. In the present study we give details on the histology and ultrastructure of its constituting elements such as oostegites and cotyledons. Marsupia of two different eco-morphological types of woodlice, namely the non-conglobating species Trachelipusrathkii Brandt, 1833 and the conglobating species Cylisticusconvexus De Geer, 1778 were investigated. Light microscopic (LM) studies showed some differences in the main structure of the two species' brood pouch: in Trachelipusrathkii, a 'clinger' type woodlice, the oostegites bend outwards during brood incubation as growing offspring require more space, while in Cylisticusconvexus, a 'roller' type isopod, the sternites arch into the body cavity to ensure space for developing offspring and still allowing conglobation of the gravid females. The quantitative analysis of the oostegites' cuticle proved that the outer part is about 2.5 - 3 times thicker compared to the inner part in both species. Electron microscopic (TEM) examinations show only small histological differences in the oostegites and cotyledon structure of the two species. Cellular elements and moderately electron dense fleecy precipitate are found in the hemolymph space between the two cuticles of oostegites. The cells contain PAS positive polysaccharide areas. TEM studies revealed some differences in the cotyledon ultrastructure of the two species. Cotyledons of Trachelipusrathkii consist of cells with cristate mitochondria and granular endoplasmic reticulum with cisterns. Cotyledons of Cylisticusconvexus consist of cells with densely cristate mitochondria and ribosomes attached to vesicular membrane structures. In both species cells with electron dense bodies were observed. We conclude that - besides the differences in marsupial shapes - the fine structure of the oostegites and cotyledons is hardly affected by the eco-morphological type, specifically the conglobating or non-conglobating character of the studied species.

No MeSH data available.


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The structure of the oostegite. A Schematic drawing of the cross -sectioned oostegite B Semithin section after PAS staining with positive cytoplasm in the cells of the oostegite C An electron micrograph of the break between cells of Trachelipusrathkii oostegite. Note scale-like protrusion of the inner cuticle (arrow) D Identical detail in Cylisticusconvexus. No protrusion was found E Cell in the oostegite of Trachelipusrathkii below a scale-like protrusion of the inner cuticle (arrow) F Cell in the oostegite of Cylisticusconvexus. Note the membrane-bound electron dense inclusions. Legends: ce – cellular elements, f – fleecy precipitate, hs – hemolymph space, ic – inner cuticle, n – nucleus, oc – outer cuticle.
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Figure 2: The structure of the oostegite. A Schematic drawing of the cross -sectioned oostegite B Semithin section after PAS staining with positive cytoplasm in the cells of the oostegite C An electron micrograph of the break between cells of Trachelipusrathkii oostegite. Note scale-like protrusion of the inner cuticle (arrow) D Identical detail in Cylisticusconvexus. No protrusion was found E Cell in the oostegite of Trachelipusrathkii below a scale-like protrusion of the inner cuticle (arrow) F Cell in the oostegite of Cylisticusconvexus. Note the membrane-bound electron dense inclusions. Legends: ce – cellular elements, f – fleecy precipitate, hs – hemolymph space, ic – inner cuticle, n – nucleus, oc – outer cuticle.

Mentions: Both species have five pairs of oostegites (on thoracic segments 1-5), that have the same structure. TEM micrographs show that the outer cuticle of the oostegites is 2.5–3 times thicker compared to the inner one in both species (Fig. 2). We confirmed the morphological observations with quantitative analysis (Table 1). The ANOVA test revealed that the values of cuticle thickness differ significantly when comparing the inner and outer cuticle of the oostegite (p < 0.001).


Histological studies on the marsupium of two terrestrial isopods (Crustacea, Isopoda, Oniscidea).

Csonka D, Halasy K, Hornung E - Zookeys (2015)

The structure of the oostegite. A Schematic drawing of the cross -sectioned oostegite B Semithin section after PAS staining with positive cytoplasm in the cells of the oostegite C An electron micrograph of the break between cells of Trachelipusrathkii oostegite. Note scale-like protrusion of the inner cuticle (arrow) D Identical detail in Cylisticusconvexus. No protrusion was found E Cell in the oostegite of Trachelipusrathkii below a scale-like protrusion of the inner cuticle (arrow) F Cell in the oostegite of Cylisticusconvexus. Note the membrane-bound electron dense inclusions. Legends: ce – cellular elements, f – fleecy precipitate, hs – hemolymph space, ic – inner cuticle, n – nucleus, oc – outer cuticle.
© Copyright Policy - creative-commons-attribution
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525037&req=5

Figure 2: The structure of the oostegite. A Schematic drawing of the cross -sectioned oostegite B Semithin section after PAS staining with positive cytoplasm in the cells of the oostegite C An electron micrograph of the break between cells of Trachelipusrathkii oostegite. Note scale-like protrusion of the inner cuticle (arrow) D Identical detail in Cylisticusconvexus. No protrusion was found E Cell in the oostegite of Trachelipusrathkii below a scale-like protrusion of the inner cuticle (arrow) F Cell in the oostegite of Cylisticusconvexus. Note the membrane-bound electron dense inclusions. Legends: ce – cellular elements, f – fleecy precipitate, hs – hemolymph space, ic – inner cuticle, n – nucleus, oc – outer cuticle.
Mentions: Both species have five pairs of oostegites (on thoracic segments 1-5), that have the same structure. TEM micrographs show that the outer cuticle of the oostegites is 2.5–3 times thicker compared to the inner one in both species (Fig. 2). We confirmed the morphological observations with quantitative analysis (Table 1). The ANOVA test revealed that the values of cuticle thickness differ significantly when comparing the inner and outer cuticle of the oostegite (p < 0.001).

Bottom Line: The quantitative analysis of the oostegites' cuticle proved that the outer part is about 2.5 - 3 times thicker compared to the inner part in both species.Cellular elements and moderately electron dense fleecy precipitate are found in the hemolymph space between the two cuticles of oostegites.We conclude that - besides the differences in marsupial shapes - the fine structure of the oostegites and cotyledons is hardly affected by the eco-morphological type, specifically the conglobating or non-conglobating character of the studied species.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Biology, Faculty of Veterinary Science, Szent István University, Rottenbiller str. 50, H-1077 Budapest, Hungary.

ABSTRACT
The marsupium, a brood pouch in peracarid crustaceans (Crustacea, Malacostraca) has evolved in terrestrial environment for providing nutrition and optimal conditions for embryogenesis. In the present study we give details on the histology and ultrastructure of its constituting elements such as oostegites and cotyledons. Marsupia of two different eco-morphological types of woodlice, namely the non-conglobating species Trachelipusrathkii Brandt, 1833 and the conglobating species Cylisticusconvexus De Geer, 1778 were investigated. Light microscopic (LM) studies showed some differences in the main structure of the two species' brood pouch: in Trachelipusrathkii, a 'clinger' type woodlice, the oostegites bend outwards during brood incubation as growing offspring require more space, while in Cylisticusconvexus, a 'roller' type isopod, the sternites arch into the body cavity to ensure space for developing offspring and still allowing conglobation of the gravid females. The quantitative analysis of the oostegites' cuticle proved that the outer part is about 2.5 - 3 times thicker compared to the inner part in both species. Electron microscopic (TEM) examinations show only small histological differences in the oostegites and cotyledon structure of the two species. Cellular elements and moderately electron dense fleecy precipitate are found in the hemolymph space between the two cuticles of oostegites. The cells contain PAS positive polysaccharide areas. TEM studies revealed some differences in the cotyledon ultrastructure of the two species. Cotyledons of Trachelipusrathkii consist of cells with cristate mitochondria and granular endoplasmic reticulum with cisterns. Cotyledons of Cylisticusconvexus consist of cells with densely cristate mitochondria and ribosomes attached to vesicular membrane structures. In both species cells with electron dense bodies were observed. We conclude that - besides the differences in marsupial shapes - the fine structure of the oostegites and cotyledons is hardly affected by the eco-morphological type, specifically the conglobating or non-conglobating character of the studied species.

No MeSH data available.


Related in: MedlinePlus