Acta Zoologica

doi: 10.1111/azo.12263pmid: N/A

Das Neves, Jamie‐Lee; Wagenaar, Ina

doi: 10.1111/azo.12246pmid: N/A

The survival of South African leopard (Panthera pardus) populations is at risk due to the decrease in natural habitat caused by increasing human populations, development projects and industry. The use of ex situ conservation methods such as assisted reproductive techniques (ARTs) in captive breeding programmes can be used to conserve and protect this species. However, a good understanding of the reproductive system of the species is imperative in the development of successful ARTs. This study serves to provide information on the morphology and ultrastructure of the spermatozoa and testes of P. pardus that can be used to help in the development, testing and optimization of reproductive techniques. The objectives of this study were (i) to assess the morphology and ultrastructure of the spermatozoa by means of fluorescence and electron microscopy respectively, and (ii) to examine the morphology and ultrastructure of the testicular tissue as well as of the stages of spermatogenesis using light and electron microscopy. In this study, it was noted that the morphology and ultrastructure of the spermatozoa are similar to those reported in other feline and mammalian species and that a high amount of morphologically abnormal ejaculated sperm was found to be a common occurrence in all samples obtained.

Germain, Damien; Meunier, François J.

doi: 10.1111/azo.12237pmid: N/A

The study of teeth of the lower jaws of Amia calva and Polypterus senegalus, with non ‐destructive X‐ray tomography, has revealed that there are dentine folds in the tooth pulp cavity in both species. These folds are simple and present only in the base of the pulp cavity where they strengthen the fixation of teeth on the jaw. So the teeth of these two basal actinopterygian taxa have a simplexodont type of plicidentine like the extinct †Cheirolepis and various extant teleostean predators, whereas the extant Lepisosteids, the sister group of Amiidae, have polyplocodont plicidentine. The phylogenetic/adaptive significance of this simplexodont plicidentine is discussed.

Schoch, Rainer R.

doi: 10.1111/azo.12238pmid: N/A

The Lower Permian temnospondyl Edops craigi exemplifies an early and plesiomorphic condition of the single ear ossicle or stapes among the temnospondyls, the probable stem group of lissamphibians. In Edops, the 11‐cm‐long bone is more massive than in other temnospondyls, has a distinct neck, a dorsal crest and incompletely subdivided footplate and ventral process. Despite a range of invariances, temnospondyl stapes were much more diverse than previously conceived. A survey of described stapes gives insight into character evolution of the ear ossicle in the lissamphibian stem group. These include alternative patterns of paedomorphosis, proportional size change, morphology of tympanic region and reorientation of the auditory apparatus.

Meng, Yinfeng; Qin, Daozheng

doi: 10.1111/azo.12239pmid: N/A

The ultramorphology of the antennae and mouthparts of the adult Loxocephala perpunctata Jacobi was studied through a scanning electron microscope. Seven types of sensilla were found on antennomeres, including a Böhm bristle on the scape, sensillum trichoideum and plaque organ on the pedicel, two subtypes of sensilla chaetica and two subtypes of sensilla campaniformia on these two antennomeres; and Bourgoin's organ with sensory pegs and sensilla basiconicum on the basal bulb of the flagellum. The mouthparts of L. perpunctata are of the typical piercing‐sucking type, similar to mouthparts found in other hemipteran insects. In general, six types of sensilla (i.e., four subtypes of sensilla chaetica, sensillum basiconicum, subapical labial sensillum, uniporous peg‐like sensillum, multiporous peg‐like sensillum and two subtypes of bristle‐like sensilla) were detected on different locations of the labium, with the last three, and numerous cuticular processes, present on the labial tip. The potential functions of these sensilla are discussed.

Andrini, Laura Beatríz; García, Marcela Nilda; Inda, Ana María; Errecalde, Ana Lía; Goin, Francisco J; Carlini, Alfredo Armando; Scarano, Alejo Carlos; Martin, Gabriel; los Reyes, Martín

doi: 10.1111/azo.12241pmid: N/A

We compare the main histological features of the digestive tract of three selected New World didelphid marsupials (Mammalia, Metatheria, Didelphimorphia, Didelphidae): the White‐eared Opossum Didelphis albiventris Lund, 1840, the Short‐tailed Opossum Monodelphis dimidiata Wagner, 1847, and the Patagonian Opossum Lestodelphys halli Thomas, 1921. The three species have a geographic distribution restricted to south‐eastern and southern South America, and have quite distinct body masses, adaptations and life histories. Our observations include the following: (i) submucosal glands are present throughout the oesophagus of D. albiventris, only in its first third in M. dimidiata, and are lacking in L. halli; (ii) in the stomach and duodenum, the serus coat coat in D. albiventris is cuboidal (simple, squamous mesothelial layer in the other two species); (iii) the duodenum in L. halli has large folds, short crypts and Brunner's glands (the other species lack folds and Brunner's glands); (iv) the colon's mucous membrane has short, scarce villi in D. albiventris (villi absent in the remaining species). Some of the observed differences can be due to ecological adaptations, especially in the relatively large‐sized, extremely omnivorous D. albiventris (e.g., colon villi).

Zaccone, Giacomo; Maina, John; Germanà, Antonino; Montalbano, Giuseppe; Capillo, Gioele; Aragona, Luisa; Kuciel, Michał J.; Lauriano, Eugenia Rita; Icardo, José M.

doi: 10.1111/azo.12242pmid: N/A

Available studies that have examined O2 sensing in fish have indicated that oxygen‐sensitive neuroepithelial cells (NECs) are O2 sensors in the gills and initiate cardiorespiratory reflexes in aquatic vertebrates. This is the first study describing the occurrence of NECs in accessory respiratory organs in the air‐breathing catfish Clarias gariepinus. Immunocytochemical stainings with specific neuronal markers such as nNOS, VAchT, 5‐HT and TH have been shown to be very useful for location and distribution of these cells in the gill fans and suprabranchial chamber that take origin from the transformation of the gill tissue. But the response of these putative O2 chemoreceptors, their role in the respiratory reflexes and their innervation await investigation.

Olivera‐Tlahuel, Claudia; Moreno‐Mendoza, Norma A.; Villagrán‐Santa Cruz, Maricela; Zúñiga‐Vega, J. Jaime

doi: 10.1111/azo.12244pmid: N/A

Both matrotrophy, the maternal provisioning of nutrients to developing embryos after fertilization, and superfetation, the simultaneous presence of two or more groups of embryos at different stages of development, occur at varying degrees among species of the fish family Poeciliidae. However, it is still unclear if these two reproductive modes depend on the presence of relatively complex placentas. We describe the ultrastructure of the maternal follicular placenta of 11 poeciliid fishes using electron microscopy. In addition, we quantified six ultrastructure characteristics that reflect the degree of complexity (number of vesicles, area of vesicles, number of microvilli, microvilli length, thickness of the maternal follicle and follicular area). Using phylogenetic comparative methods, we evaluated the relationship between degree of matrotrophy and placental characteristics. We also analysed the potential effect of the presence of superfetation on placental complexity. We found a positive relationship between the degree of matrotrophy and follicular area, number of microvilli and number and area of vesicles. Similarly, follicular area and number of microvilli were larger in species with superfetation than in those without superfetation. We conclude that high degrees of matrotrophy and superfetation are associated with placental characteristics that increase the efficiency of nutrient transfer between mother and embryos.

Klećkowska‐Nawrot, Joanna E.; Goździewska‐Harłajczuk, Karolina; Darska, Marta; Barszcz, Karolina; Janeczek, Maciej

doi: 10.1111/azo.12251pmid: N/A

This study described the anatomy, histology and the histochemical analysis of the eye tunics, the upper and lower eyelid, the third eyelid, the lacrimal gland and the superficial gland of the third eyelid in adult Sulawesi bear cuscus. The eyeball and the eyelids with the orbital glands were harvested immediately post‐mortem. The eyeball in the Sulawesi bear cuscus had a sphere‐like shape. The pupil was round, and the lens was a circular biconvex body. There was neither tapetum lucidum nor Harderian gland. Similarly, there were no eyelashes in the lower eyelid. The lymphoid follicles and the high endothelial venules (HEV) were found in the lymphoid region only in the third eyelid and in the connective tissue of the superficial gland of the third eyelid. The third eyelid in the bear cuscus resembled the letter “T.” The lacrimal gland and superficial gland of the third eyelid were multilobar tubuloacinar glands. The histological analysis and histochemical studies showed that the lacrimal gland in the Sulawesi bear cuscus produced a mucoserous secretion with predominantly serous cells. In contrast, the superficial gland of the third eyelid produced a serous secretion with a single acinus mucous in character.

Bartolini Lucenti, Saverio

doi: 10.1111/azo.12232pmid: N/A

The molar ratio method presented by Acta Zoologica (98, 2016, 292) is a valid way to estimate the dietary differences between extant subspecies of the raccoon dog genus, Nyctereutes. Particularly, higher values of the molar ratio implies more omnivous diet than lower ones. With the same technique is possible to infer variations in the diet of extinct species. For the two Plio‐Pleistocene fossil species Nyctereutes sinensis and Nyctereutes megamastoides, the authors estimate a more carnivorous diet for the latter in comparison to the former that has much higher values. This fact contrast with the morphological features of these two highly comparable species, often considered as morphotypes of the same species. Thanks to the revision of a large sample of N. sinensis from Chinese localities of the Yushe Basin (Shanxi Province), new scores for this species have been calculated. The results presented here confirms a strong adaptation to an omnivorous diet, as emerged from morphofunctional evidence in recent literature.