Pathologic findings in weedy (Phyllopteryx taeniolatus) and leafy (Phycodurus eques) seadragons.

A retrospective study of the pathologic findings in weedy (Phyllopteryx taeniolatus) and leafy (Phycodurus eques) seadragons was performed on specimens submitted to 2 reference laboratories from 1994 to 2012 to determine the range and occurrence of diseases affecting aquarium-held populations. One hundred two and 94 total diagnoses were recorded in weedy and leafy seadragons, respectively. Two of the more common etiologic diagnoses in both species were mycobacteriosis and scuticociliatosis, whereas myxozoanosis was common in weedy seadragons. Metazoan parasite infections were less common etiologic diagnoses. There were no correlations between mycobacteriosis and ciliate protozoan infections in either species. Myxozoanosis was usually found in combination with other diseases and, except for 1 case, was restricted to weedy seadragons. Phaeohyphomycosis, nonmycobacterial bacterial infections, and trauma were also important but less frequent diagnoses. Intestinal coccidiosis was found in weedy but not leafy seadragons. Mineralization of the swim bladder was detected in 26 of 197 leafy seadragons and only 2 of 257 weedy seadragons. Although weedy and leafy seadragons share certain diseases of significance to exhibit populations, there are diseases unique to each species about which the veterinary pathologist, clinician, or diagnostician should be aware.

Species-specific distributions of tyrosine hydroxylase-immunoreactive neurons in the prefrontal cortex of anthropoid primates.

In this study, we assessed the distribution of cortical neurons immunoreactive for tyrosine hydroxylase (TH) in prefrontal cortical regions of humans and nonhuman primate species. Immunohistochemical methods were used to visualize TH-immunoreactive (TH-ir) neurons in areas 9 (dorsolateral prefrontal cortex) and 32 (anterior paracingulate cortex). The study sample included humans, great apes (chimpanzee, bonobo, gorilla, orangutan), one lesser ape (siamang), and Old World monkeys (golden guenon, patas monkey, olive baboon, moor macaque, black and white colobus, and François' langur). The percentage of neurons within the cortex expressing TH was quantified using computer-assisted stereology. TH-ir neurons were present in layers V and VI and the subjacent white matter in each of the Old World monkey species, the siamang, and in humans. TH-ir cells were also occasionally observed in layer III of human, siamang, baboon, colobus, and François' langur cortex. Cortical cells expressing TH were notably absent in each of the great ape species. Quantitative analyses did not reveal a phylogenetic trend for percentage of TH-ir neurons in these cortical areas among species. Interestingly, humans and monkey species exhibited a bilaminar pattern of TH-ir axon distributions within prefrontal regions, with layers I-II and layers V-VI having the densest contingent of axons. In contrast, the great apes had a different pattern of laminar innervation, with a remarkably denser distribution of TH-ir axons within layer III. It is possible that the catecholaminergic afferent input to layer III in chimpanzees and other great apes covaries with loss of TH-ir cells within the cortical mantle.

Relationship of premaxillary bone and its sutures to deciduous dentition in nonhuman primates.

OBJECTIVE: The relationship of the human premaxillary bone (Pmx) to neighboring craniofacial structures is clouded by its embryonic union with the maxillary bone proper. Only humans among all primates have such early fusion of the premaxillomaxillary suture (PS). This study surveyed the relationship of the PS to the upper deciduous dentition in nonhuman primates, and describes the distribution of bone cells along the osseous margins of the Pmx. METHOD: Twenty-eight subadult primates were studied using gross, CT, and histologic observations. Location of the anterior deciduous dentition relative to the PS was assessed. In sections of selected specimens, observations of bone cells on the osseous boundaries of the Pmx were made. Osteopontin (OPN) immunohistochemistry was used to isolate osteoclastic binding sites along the Pmx boundaries. RESULTS: The PS was consistently found between deciduous incisor and canine in strepsirrhines of all ages, whereas the suture passed variably closer to the incisor or canine in haplorhines. In all species, the anterior part of the Pmx was nonarticulating and mostly osteoblastic, except for osteoclastic margins adjacent to dentition and the nasal fossa. Superolaterally, the osteogenic fronts of the PS were osteoblastic, while more inferiorly, at the level of the deciduous canine, the PS was often osteoclastic. Results from OPN immunohistochemistry support the findings on bone cell distribution. CONCLUSION: Bone cell distribution patterns in perinatal nonhuman primates resemble those described for the prenatal human Pmx, suggesting that differences among species relate to magnitude rather than the pattern of osteogenesis.

The existence of the vomeronasal organ in postnatal chimpanzees and evidence for its homology with that of humans.

It is currently thought that New World monkeys, prosimians, and humans are the only primates to possess vomeronasal organs (VNOs) as adults. Recent studies of the human VNO suggest that previous investigations on Old World primates may have missed the VNO. We examined nasal septa from the chimpanzee (Pan troglodytes) grossly and histologically for comparison with nasal septa from humans, Old World monkeys (Macaca fascicularis, M. nemistrina) and prosimian primates (Microcebus murinus, Otolemur garnettii). Grossly, chimpanzees had depressions on the nasal septum similar to fossae reported anterior to the VNO openings in humans. Histologically, chimpanzees and humans had bilateral epithelial tubes which were above the superior margin of the paraseptal cartilages (vomeronasal cartilage homologue). The epithelial tubes had a homogeneous ciliated epithelium. These structures were thus positionally and structurally identical to the human VNO and unlike the well-developed prosimian VNOs which were surrounded by vomeronasal cartilage. Macaques had no structures which resembled the VNO of either the prosimians or humans. The results demonstrate that the VNO is present postnatally in the chimpanzee and is almost identical to the human VNO in its anatomical position and histological structure. This in turn suggests that the reported absence of the VNO in at least some adult Old World primates is artifactual, and that further study may provide evidence for its existence in other species.