Nicolau, C.F., Nascimento, A.A., Machado‐Santos, C., Sales, A. and Oshiro, L.M.Y. 2011. Gonads of males and females of the mangrove tree crab Aratus pisonii (Grapsidae: Brachyura: Decapoda): a histological and histochemical view. —Acta Zoologica (Stockholm) 00:1–9. This study describes the microscopic anatomy of the male and female gonads and the spermatogenesis and oogenesis of the mangrove tree crab Aratus pisonii. Males and females were captured in a mangrove marsh in Guaratiba (23°04′S, 44°10′W), Rio de Janeiro State, Brazil. The testes are composed of spermatogonia I (7.82 ± 0.84 μm), spermatogonia II (6.12 ± 0.72 μm), spermatocytes I (5.62 ± 0.71 μm), spermatocytes II (5.00 ± 0.42 μm), spermatids (4.01 ± 0.33 μm), and spermatozoa (2.58 ± 0.18 μm). The spermatozoids are sent to the vas deferens, which is divided into three regions: anterior vas deferens, middle vas deferens and posterior vas deferens. There are no indications of development as the production of male gametes was continuous throughout the study period. In the females, there are four ovary development stages: previtellogenesis, early‐stage vitellogenesis, mature vitellogenesis, and postspawning. Five types of cells were found in the gonads: oogonia (5.23 ± 1.31 μm), oocytes in early development (19.84 ± 5.16 μm), previtellogenic oocytes (49.49 ± 6.87 μm), vitellogenic oocytes (87.51 ± 10.23 μm), and mature oocytes (174.78 ± 29.46 μm). The findings of this study indicate that A. pisonii females lay eggs on multiple occasions throughout the study period.

The stomach of Rhinella icterica was analyzed at light microscopy, employing histochemical techniques, lectin histochemistry, and immunohistochemistry for identifying enteroendocrine cells (EC). Although the stomach was composed of fundic and pyloric regions, its wall is formed by mucosa, submucosa, muscularis, and serosa. The mucosa was lined by a simple columnar mucous epithelium, supported by loose connective tissue. Several tubular, simple glands were composed of mucous neck cells, containing oxynticopeptic cells and EC cells. The mucous neck cells were rich in neutral glycoconjugates. The oxynticopeptic cells were predominant in fundic glands, exhibiting weaker alcianophilic reaction at their apical cytoplasm. Serotonin (5-HT) immunoreactive (IR) cells occurred throughout the entire stomach, preferentially located among mucous cells at upper part of the fundic glands. The muscularis mucosae, formed of smooth muscle, separated the mucosal layer from the submucosa, both of which were constituted by loose connective tissue, but without glands. Lymphoid modules occurred in the mucosa at the boundary at the stomach and the gut. In addition, the muscularis was constituted by two sublayers, the circular internal and the longitudinal external, being recovered by the connective tissue of the serosa.

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Pelli-Martins, A.A., Machado-Santos, C., Sales, A. and de Brito-Gitirana, L. 2012. Histochemical, immunohistochemical, and ultrastructural observations of the esophagus morphology of Rinella icterica (Anuran, Bufonidae). -Acta Zoologica (Stockholm) 93: 373-380.The esophagus of Rinella icterica was analyzed by employing histochemical methods and lectin histochemistry at light microscopy as well as by transmission electron microscopy. The mucosa was composed of a ciliated columnar pseudostratified epithelium with goblet cells, overlying a lamina propria. The goblet cells contained neutral and acid glycoconjugates and were positive for galactose residues. Moreover, two types of goblet cells were identified; one type was positive for mannose, and the other was negative. Serotonin-immunoreactive cells (5HT-IR) occurred randomly scattered at the base of the epithelium; they were also localized between the mucous cells of the gland. Both submucosa and adventitia were composed of loose connective tissue, and the muscularis was formed by smooth muscle. Although the basic morphology of the esophagus of R. icterica is similar to that of mammals, the esophagus showed some morphological differences that are likely to be related to the specific physiology of the tissue.

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The broad-snouted caiman, Caiman latirostris, is widely distributed in countries of South America. In Brazil it is considered an endangered species because of natural habitat destruction and illegal hunting. In reptiles, the thyroid gland plays an integral part in ecdysis, reproduction, tail regeneration, growth, endocrine function and metabolism rate. The aim of the present study was to characterize the thyroid gland morphology of C. latirostris, based on histochemical and immunohistochemical techniques. The thyroid glands were fixed in Bouin's fluid and serial cross sections were stained with hematoxylin-eosin, Mallory's trichrome, periodic acid-Schiff (PAS) and Alcian blue (AB pH 1.5 and 2.5). The immunohistochemical technique for 5-HT-IR cells was used. The thyroid gland has a dense irregular connective tissue forms a capsule enveloping the gland. There are several follicular acini of varying size lined by simple cuboidal or columnar epithelium in the thyroid gland. The follicles are connected by interfollicular connective tissue which contains blood vessels. We observed the presence of lymph nodes around the entire gland. There was a positive PAS reaction and negative AB reaction in the colloid. 5-HT-IR cells were detected around the follicle cells. No striking morphological differences were observed between C. latirostris and other domesticated mammals.

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