Lobulation pattern of the of the cerebellum of African grasscutter (Thryonomys swinderianus)

Grasscutter is one of the largest species of rodents in Africa whose basic cerebellar folding pattern has not been documented. The aim of the research was to provide reference data on the lobulation morphometric of its cerebellar cortex. A quantitative analysis was conducted on the cerebella of seven African grasscutters. The results showed that the head weight had strong positive correlation with the cerebellar weight (r = 0.8954, P < 0.001). In the rostral lobe, the mean size of declive was significntly larger than Lingula cerebelli (P < 0.01) and culmen (Pars caudalis) (P < 0.001). Also, the culmen Pars rostralis differed signigifcantly with Pas caudalis (P < 0.01). For the Lobus caudalis, the mean folium vermis was significantly higher than those of the tuber vermis and nodulus (Ps < 0.001). The ovula vermis was the broadest lobule in this lobe, was significantly larger than the tuber vermis the pyramis, and nodulus (Ps < 0.001). The mean internal perimeter, including all primary and secondary sublobules (4643.3 ± 341.69 μm) was higher than the external perimeter (1621 ± 42.43 μm) significantly (P < 0.0001). The mean cerebellar foliation index was 2.86 ± 0.18; suggesting a relatively increased in length of cerebellum in form of a folded structure. In conclusion, some of the structural development and behaviours in the grasscutter may likely be correlated with the relative sizes of individual cerebellar lobules.Keywords: Cerebellum, lobes, lobules, morphometric, T. swinderianu

Structural organization of the olfactory bulb of wild ferret pigeon (Columba livia)

Fourteen brain samples (Ten for morphometry, two for gross and two for histological studies) were used in this study. The mean body weight of the wild ferret pigeon was 214 ± 13.37 g. The brain weight, length and width obtained from this study was 1.61 ± 0.07 g, 11.41 ± 0.25 cm and 15.62 ± 0.25cm. The mean height and volume were 12.04 ± 0.30 cm and 1.66 ± 0.9 cm3. There were significant differences between mean brain weight and volume. Morphologically, the olfactory lobe was observed to be bilobed structures on the rostro-ventral aspect of the cerebral hemispheres and was smaller compared to the entire cerebrum. The cellular layer was observed to be made up of; the olfactory nerve layer, glomerular layer, mitral cell layer and granule cell layer. The mitral or tuft cells resembles small pyramidal cells whose nuclei were centrally located, dark stained and are principal neurones of the olfactory lobe. Some of the processes were directed towards the granule and glomerular layers. The granular cells were numerous with dark stained nuclei. There is a corresponding increase in the brain volume as the brain weight increases. Grossly, the olfactory bulb is not developed. The mitral cell confers olfaction in animals as such, this bird has better olfaction compare to other birds.Keywords: Structural, organization, olfactory, wild, pigeo

Study on the macrometry of gastrointestinal tract of wild west African Senegal parrot (Poicephalus senegalus versteri)

Parrots are ornamental birds that are found in the wild and those in domestication end up in animal units of schools and houses of the wealthy individuals. The wild African Senegal parrot population is at risk of extinction due to its high popularity with urban dweller. Despite their high popularity, there is scanty documentation of the anatomical features of its gastrointestinal tract (GIT). The Wild West African Senegal Parrots were caught around forested area of a farm settlement in Shika, Zaria, Kaduna state, in the Northern part of Nigeria. The mean body weight of the wild Senegal parrot was observed to be 120.50 ± 5.42 g. The mean weights of the GIT with content and without content were 18.01 ±4.80 g and 13.54 ± 5.51 g respectively which accounted for 12.95 % and 10.24 % of the total body mass. The mean weights (small and large intestines) were 2.10 ± 1.09 g and 0.70 ± 0.27 g. The caecum was not noticed and gall bladder had the least mean weight 0.17 ± 0.007 g. while the gizzard the highest of all mean weight 4.28 ± 2.25 g. The mean lengths (GIT, small and large intestines) were; 82. 61 ± 2.36 cm, 41.75 ± 2.97 cm and 18.06 ± 2.01 cm. The glandular area of the proventriculus was longer than the non glandular portion and the left liver was longer compared to the right 3.03 ± 1.53 cm. The ileum is the longest segment of the small intestine which constituted 22.90 ± 2.92 cm.Keywords: Macrometry, Gastrointestinal Tract, Senegal Parrot

Comparative topographic analyses on the foramen magnums of two hystricomorphs: the crested porcupine (Hystrix cristata) and greater cane rat (Thryonomys swinderianus). Implications for typology, phylogeny and evolution in rodents

Background: This investigation aims to assess species comparison of foramen magnums in two hystricomorphs and endeavours an inter-species categorisation of individual shape outline. Materials and methods: This study utilised 35 skull samples of different ages from the crested porcupine (H. cristata) (17) and the greater cane rat (T. swinderianus) (18) through. Elliptical Fourier Analysis, and the two-block Partial Least Squares analysis. Elliptical Fourier descriptor analyses presented marked amplitude related attenuations according to harmonics factor (1/10 to 2,980) in T. swinderianus though angular orientations in the major axis were not profoundly affected by size-normalisation in this species but up-regulated in H. cristata; (1/10 to1/95). Results: Within and between groups analyses revealed PC1&2 contributed 98.94% and 1.06% but 100% PC1 between groups. The 1st to 4th harmonics gave full topographic description of the foramen magnums in both, 1st–3rd harmonics details compared differently revealing shape variance concentrated in posterolateral and posterior regions of the foramen magnum in the porcupine but antero-lateral and dorsal in cane rats, components of morphological asymmetry were demonstrated from 6th to 12th harmonics. Stepwise discriminant analysis of harmonic increments and Mahalanobis distance exposed increasing disparities between both up to the 5 th harmonic (Bonferroni-corrected p-values [277.2, p < 0.002] group centroids) and a slightly lower value in variance for cane rats 0.421 and 0.378 for porcupines. A (58.3% and 33.3%); (94.1% and 11.1%) proportion before and after size-normalised evaluations of porcupines and cane rats size factor removal yielded 35.8% increase in accuracy among crested porcupines but 22.2% decline in cane rats. Dimorphic variations were less frequently expressed in cane rats corresponding to 33.3% and 44.2%. Size normalisation effect brought a reverse situation with an increased difference (11.1% in T. swinderianus; 5.9% in H. cristata). Individual specimen distribution along discriminant axis pooled by discriminant scores depicted less morphologic variability with greater overlaps. Conclusions: We observe that complexities in foramen magnum architecture between these indicates parcellation of shape and size variance and contributes as evidence for structural evolution, systematics, fundamental similarities and differences offers an explanation that both are related through evolutionary proces of descent as baseline data and further support the suggestion; hystricidae in phylogenetic tree are better evolved and separate from thryonomidae

Rostro-dorsal and rostro-lateral skull morphologic variability in three age-groups of the Egyptian mongoose (Herpestes ichneumon) (Linnaeus, 1758): implications of certain orbital parameters — angular geometric approach

This study evaluated 30 skulls of the grey mongoose divided into three age-groups (6 pups, 10 juveniles and 14 adults) for skull shape variability determination. Specific geometric shapes were drawn from defined points. Angular geometric measurements of shapes derived from rostro-dorsal and rostro-lateral parts of the skull included; orbital angles (with and without the mandible), comprising of viscero-cranium, skull and orbital index that was calculated to evaluate the correlations, if any, with angles measured. It was observed that orbital height and width became higher with age; there was stronger correlation in this regard between pups and juveniles compared with juveniles and adults. There is a reduction (narrowing) in BrEcEc, BrEcN, EcPEc, EcEnN and NwNNw angles with concomitant enlargement of BrEcP, BrEcN, EcNEc, EnNEn, EcNNw and EnNP with age. The decline in the skull index shows a decrease in rate of skull width growth relative to rostro-facial length and demonstrates non-proportionality to zygoma bowing. Significantly varied orbital parameters include the inter-canthii distance and implications of certain significant variables observed in some geometric orbital measurements of the tropical mongoose (Herpestes ichneumon). The survey hypothesizes the observations follow typical carnivoran phylogenic affinity, differentiates this species from similar herpestid versions and is an estimation of functional morphology with respect to bite size. It is further suggested to contribute to visual acuity in timing of bite delivery as well an adaptation in prey summarisation. This study will serve as baseline information in herpestid cranial investigations. Such facial features are useful in population studies, species identification, eco-migrant species surveillance and species ontogenic evolution

Morphogenesis of the midbrain of grey breasted helmeted guinea fowl at pre-hatch

This study was carried out to investigate the development of the midbrain in the grey breasted helmeted guinea fowl. Domestication of grey helmeted guinea fowl is increase but scanty documentation on the development of midbrain (mesencephalon) and how it relates to the neurobiology of this bird is lacking. A total of sixty six (66) fertilized guinea fowl eggs were purchased from National Veterinary Research Institute (NVRI) Vom, Jos, Plateau state, Nigeria and used for this study. Grossly, in the wild grey breasted helmeted guinea fowl, the optic lobe develops following development of midbrain and the midbrain appeared first on day 10 of incubation flank by the optic lobes on each sides. There was steady increase in the weights of the midbrain up to day 28 of incubation. This was expressed graphically at pre-hatch period which went up at day 17 and dropped at day 20 of incubation. Significant increases (P ≤ 0.0001) of the midbrain were seen on days 23 and 26. This indicates that as body and brain weights were increasing, there was a concurrent increase in midbrain weight. Morphologically, the midbrain was fully developed at pre-hatch period. This indicates that contribution from optic lobe to auditory-visual systems is fully developed in the wild grey breasted helmeted guinea fowl immediately after hatching and is capable of surviving independently.Keywords: Grey, Helmeted, Midbrain, Morphogenesis, Pre-hatc

Brain Size of the African Grasscutter (Thryonomys Swinderianus, Temminck, 1827) at Defined Postnatal Periods

As a sequel to the current advancement in ethology, this study was designed to provide information on the brain size of the African grasscutter at specific postnatal periods and to extrapolate these findings to the behaviour of the rodent in its natural habitat. Brain samples were extracted from African grasscutter neonates on postnatal day 6, juveniles on postnatal day 72 and adults on postnatal day 450 by basic neuro-anatomical techniques. The weight, volume and dimensions of the brain samples were determined in absolute and relative terms. Their encephalisation quotient was also computed. There was a very strong positive correlation between nose-rump length and brain length in the neonates. The relative brain weight of neonates, juveniles and adults were 3.84 ± 0.12 %, 2.49 ± 0.07 % and 0.44 ± 0.03 %, respectively. The differences were significant (P < 0.05). The encephalisation quotient of juveniles was 1.62 ± 0.03 while that of the adult was 0.49 ± 0.02. The difference was significant (P < 0.05). The results were extrapolated to the animal’s cognitive ability, and compared with other rodents. It was concluded that the juvenile African grasscutter may have higher cognitive ability than the adult rodent, thus, juveniles should be preferred in physiological studies of memory and cognition

Polymelia, vent duplex, cloacal bursa duplex and triple caeca in a broiler chick

Congenital abnormalities are common among avian and mammalian species. They could be partial or total drift from the normal structural organization of the organ-systems. This article is aimed at reporting the occurrence of multiple abnormalities in a 3-week-old broiler chick. Ante mortem, post-mortem, radiological and osteological investigations were carried out, to ascertain the number and form of abnormalities present in the chick. A total of four different congenital abnormalities were discovered in this chick. These include: polymelia (presence of supernumerary or accessory limb which is usually malformed); double vents (vent duplex); double cloacal bursae (bursa duplex) and triple caeca. Radiological and postmortem examinations revealed the attachment of the accessory limb to the caudal depressor muscle as a form of synsarcosis, via a tendon that originated from the deep fossa of the modified femoral head of the accessory limb. The right vent was patent whereas the left was not. The two cloacal bursae were almost the same size, while the three caeca showed slight variation in length but typical features of the avian caecum (base, middle (body) and apex) were clearly visible. However, most cases of congenital anomalies in the avian species occur as multiple defects, with the most common being polymelia. The latest finding in this report is the discovery of double cloacal bursae (bursae of Fabricius), which has not been reported in the avian species