Darwin and the cirripedes: Insights and dreadful blunders

Charles Darwin's favorite animals were cirripedes (barnacles). Indeed, he worked intensively on cirripedes during the years he was maturing his thoughts regarding his theory, which eventually led to the publication of The Origin of Species. Here I present some of Darwin's achievements in the morphology, systematics and biology of these small marine invertebrates, and also, in light of our present knowledge, some mistakes he made.     

The “Tears of the Virgin” at Lakes Entrance,southeast Australia were made by the intertidal barnacle Chthamalus antennatus (Cirripedia: Thoracica) and cyanobacteria

Curious eroded depressions, most resembling an eye shedding an elongate tear, are found in gently sloping, intertidal, carbonate‐rich arenite outcropping on the sea coast near Lakes Entrance, Victoria, southeast Australia. The depressions, known locally as “Tears of the Virgin,” are evidently formed by multiple generations of a barnacle, Chthamalus antennatus Darwin, 1854 in association with cyanobacteria. While the round part of a depression offers the barnacle a modicum of protection from impacts during high tides, it is also partially inhabited by cyanobacteria, which extend into and tend to fill the elongate tear. As such, this appears to be the first case of mutualism between a higher invertebrate and cyanobacteria, with the cyanobacteria reducing the barnacle's risk of desiccation while receiving metabolic wastes from it during low tides. It is also the first record of a balanomorph barnacle eroding calcareous arenite beneath its shell, the net effect of which would be expected to reduce its adhesion to the substrate. However, the siliceous residue, resulting from the barnacle's dissolution of the more than 80% of the calcite‐rich sedimentary rock, is sequestered in delicate folds on the inside of the shell wall as it grows. A brief review of cirripedes capable of excavation includes the first photographic documentation of excavation of a mollusc shell by a verrucomorph.     

Influence of ante‐ and peri‐mortem factors on biochemical and physical characteristics of turkey breast muscle

Summary

The course of post‐mortem breakdown of glycogen and ATP in turkey pectoralis major muscle was markedly influenced by several ante‐ and peri‐mortem variables. Application of a proper stunning procedure was highly effective in preventing peri‐ and post‐mortem muscle stress reactions.

The physiological level of glycogen and ATP was not significantly affected by road transportation covering 260 km. Birds which rested for 24 hrs following transportation had lower glycogen and ATP levels at the moment of slaughter than non‐rested birds.

According to the changes in the rate and extent of post‐mortem biochemical reactions, several meat characteristics such as water‐holding capacity, colour, and tenderness were significantly changed.

Furthermore, the results also indicate that turkey breast muscle is susceptible to a PSE‐like condition as described in pork.     

Evaluation of Three Different Extenders for Use in Emergency Salvaging of Epididymal Spermatozoa from a Cantabric Brown Bear

The Cantabrian brown bear (Ursus arctos) constitutes an endangered subpopulation of the European brown bear in the north of Spain. We have carried out a post‐mortem recovery of epididymal spermatozoa from a Cantabrian brown bear (7 years old, 170 kg; 30 min post‐mortem), cryopreserving those recovered from the cauda epididymis (929 × 10⁶ spermatozoa, 54% motile, 82% cytoplasmic droplets). For freezing, three extenders based on Test‐Tris‐Fructose + 4% glycerol were used: (1) 325 mOsm/kg and 10% egg yolk; (2) 430 mOsm/kg and 15% egg yolk; (3) 300 mOsm/kg, Equex‐EDTA and 20% egg yolk. After thawing, we obtained higher motility for extender 3 (31%), but extender 2 yielded the highest viability (66.9%) and mitochondrial activity (67.1%). Caffeine stimulation showed that extender two rendered the highest recovery values of post‐thawing motility with respect to the fresh sample. In conclusion, epididymal spermatozoa of brown bear can be frozen applying an extender with osmolality similar to epididymal environment.     

Pathology of gastritis and gastric ulceration in the horse. Part 1: Range of lesions present in 21 mature individuals

Reasons for performing study: Gastric ulceration is now widely recognised as an important disease in high performance horses. Little is known about gastric histopathology in healthy or diseased animals; a comprehensive assessment would enhance interpretation of gross findings through assessment of their accuracy and allow for identification of lesion variety and pathogenesis in different anatomical regions of the stomach. Objectives: To investigate the true extent and variety of gastric lesions in a mixed population of mature horses at post mortem. Methods: Stomachs were removed from a mixed population of 21 horses at post mortem. Mucosal abnormalities were recorded in photographic and written form. Representative samples from all gross lesions were taken for histopathology and processed routinely. Special stains including Gram, PAS and Warthin Starry, were used when appropriate. Pathological classification of lesion type using both gross and histological appearances was performed. Results: Classification of lesions within the squamous region included hyperkeratosis, punctate scars, diffuse erosions/ulcerations and margo injuria; and within the glandular region, hyperaemia, focal erosions and ulcerations. Glandular metaplasia was recognised for the first time in the equine stomach. No Helicobacter‐like organisms were detected in association with lesion development. Conclusions and potential relevance: This study used gross and histological examination to highlight the large variety of naturally occurring gastric lesions in a mixed population of horses. Analysis of the pathogenesis of lesion development is now possible. Further research regarding the range of pathology in larger, more diverse groups of horses is required.     

Concurrent atypical myoglobinuria and colon displacement in a filly

An 18‐month‐old pony filly was examined for acute colic and abdominal distension. The signs of colic failed to resolve following analgesic treatment. At exploratory laparotomy, a right dorsal displacement of the large colon was identified and corrected. On recovery from anaesthesia, the pony developed signs of widespread myopathy, confirmed by serum biochemistry evaluations. Myopathy consistent with atypical myoglobinuria was confirmed post mortem.     

Differences in calpain system,desmin degradation and water holding capacity between commercial Meishan and Duroc × Landrace × Yorkshire crossbred pork

The objective of this study was to examine the differences in calpain system, desmin degradation, pH values and water holding capacity (WHC) between muscles of commercial Meishan and Duroc × Landrace × Yorkshire crossbred pigs. Meishan pork presented better WHC evidenced by lower purge loss at days 1 and 3 and less centrifugation loss at day 1 post mortem (P < 0.05). pH values at 45 min post mortem in Meishan pork were significantly higher compared to crossbred pork (P < 0.05). Calpain‐1 messenger RNA (mRNA) expression was lower in Meishan pork compared to that from crossbred pork (P < 0.05). Additionally, calpain‐1 activity, the ratio of calpain‐1 to calpastatin activity and desmin degradation were lower in Meishan pork compared to those from crossbred pork samples (P < 0.05). The results indicate that the calpain system including mRNA expression and activity were different between commercial Meishan and crossbred pork resulting in difference in the degree of desmin degradation during post mortem aging. pH values at 45 min and 24 h post mortem rather than calpain activity and desmin degradation could explain the higher water holding capacity in commercial Meishan pork.     

Opportunism and the resilience of barnacles (Cirripedia: Thoracica) to environmental change

Cirripede-like organisms have their origins in the Palaeozoic, but until the Cainozoic, were represented primarily by pedunculated forms, such as the Scalpelliformes. Acorn barnacles (Balanomorpha) are first recorded after the Cretaceous-Tertiary extinction event. During the late Palaeogene, rapid radiation of cirripedes resulted in sufficient diversification for them to occupy most marine environments. That they survived both the Palaeocene-Eocene Thermal Maximum and the Pleistocene glaciation is testament to their ability to rapidly adapt to opportunities. The wide habitat distribution of balanomorphs in particular is unparalleled; they are known from the upper littoral (Chthamalus) to depths of 3600 m (Tetrachaelasma) and within this attached to rock, wood and miscellaneous flotsam, plus in symbiosis or commensalism with larger marine organisms. Darwin's (1854) view of the Tertiary as the age of barnacles is reflected in this diversity, distribution and biomass. All cirripedes are, nonetheless, at risk, from rapid habitat change, competition, pollution and, especially in light of their sessile habit, from predation. This paper assesses the viability of a number of cirripedes and concludes that the Lepadiformes, Scalpelliformes and Balanomorpha are the most resilient, and will most quickly adapt to occupy new niches when opportunities arise.     

Early Postnatal Development of the South African Hamster Mystromys Albicaudatus

The starfish Marthasterias glacialis is a generalized predator, feeding particularly on Choromytilus meridionalis, but also on several limpets, notably Patella longicosta. Thais dubia (Gastropoda) feeds mainly on barnacles, mussels, and Patella granulans. The gastropods Burnupena delalandii and B. cincta are principally scavengers, feeding on damaged or dead animals. The responses of Patella spp. to these predators are described. P. granulans, P. concolor, P. compressa and P. miniata all retreat rapidly on contact. Small P. granatina and P. oculus respond similarly, but larger specimens react aggressively, smashing their shells downwards and often damaging the predator. The territorial species (P. longicosta, P. cochlear and P. tabularis) all retreat to their scars and remain clamped there. P. argenvillei and P. tabularis are usually unresponsive, possibly because they are too large to fall prey. Cellana capensis rolls its mantle upwards to cover the shell, preventing predators from attaching. The responses and their effectiveness are discussed in relation to other behavioural patterns displayed by limpets. There is no correlation between the intensity of a prey’s response to a predator and the degree of contact between the two in the field.     

Pyothorax associated with a Mycoplasma species in a kitten

A 12-week-old kitten with congenital mitral valve dysplasia was shown by ante mortem and post mortem examination to have pneumonia and purulent pleurisy. A Mycoplasma species was isolated from a sample of pleural fluid collected at necropsy. Mycoplasmosis should be considered in the differential diagnosis of pyothorax in cats.     

Changes of microbial spoilage,lipid‐protein oxidation and physicochemical properties during post mortem refrigerated storage of goat meat

Examined was the effect of post mortem refrigerated storage on microbial spoilage, lipid‐protein oxidation and physicochemical traits of goat meat. Seven Boer bucks were slaughtered, eviscerated and aged for 24 h. The Longissimus lumborum (LL) and Semitendinosus (ST) muscles were excised and subjected to 13 days post mortem refrigerated storage. The pH, lipid and protein oxidation, tenderness, color and drip loss were determined in LL while microbiological analysis was performed on ST. Bacterial counts generally increased with increasing aging time and the limit for fresh meat was reached at day 14 post mortem. Significant differences were observed in malondialdehyde (MDA) content at day 7 of storage. The thiol concentration significantly reduced as aging time increased. The band intensities of myosin heavy chain (MHC) and troponin‐T significantly decreased as storage progressed, while actin remained relatively stable. After 14 days of aging, tenderness showed significant improvement while muscle pH and drip loss reduced with increase in storage time. Samples aged for 14 days had higher lightness (P < 0.05) and lower (P < 0.05) yellowness and redness. Post mortem refrigerated storage influenced oxidative and microbial stability and physico‐chemical properties of goat meat.     

Infective polyarthritis and multiple discospondylitis in a dog due to Erysipelothrix rhusiopathiae

A seven-month-old Irish wolfhound suffered an infectious polyarthritis and multiple discospondylitis. Erysipelothrix rhusiopathiae was cultured from several of the joints at post mortem examination.     

VALIDATION OF A NOVEL TRANSLUMBAR ULTRASOUND TECHNIQUE FOR MEASURING RENAL DIMENSIONS IN HORSES

A reliable method for obtaining renal ultrasonographic measurements in the horse is important for diagnosis and monitoring of clinical renal disease. The aims of this prospective study were to develop and validate a novel translumbar ultrasound technique for measuring renal dimensions in horses. Six Thoroughbred or Thoroughbred part bred horses were recruited. All horses were scheduled for euthanasia due to reasons unrelated to the kidneys. Two observers recorded renal length, width, and depth; and dimensions of the cortex, medulla, pyramids, and pelvis for both kidneys in each horse using novel translumbar and conventional transabdominal ultrasound methods. The same measurements were recorded from post‐mortem renal specimens. Both kidneys were consistently identified by both methods in the 15–17th intercostal spaces and paralumbar fossa. Using the translumbar technique, maximal dimensions were obtained for the left kidney in the 16th intercostal space (length 16.2 ± 2.0 cm, width 11.8 ± 0.5 cm, depth 6.4 ± 0.9 cm) and for the right kidney in the 15th intercostal space (length 16.1 ± 1.2 cm, width 13.4 ± 1.2 cm, depth 6.7 ± 0.7 cm). Renal dimensions obtained by transabdominal and translumbar projections did not differ (P > 0.05). Good correlations were found between overall renal dimensions and post‐mortem measurements for both ultrasound techniques (r² > 0.8), but were better for the translumbar method (mean r² = 0.92 cf. 0.88). Good‐to‐excellent reliability was found for all translumbar ultrasound measurements except for the renal cortex. Reproducibility was better for the larger (overall length, width, and depth) than the smaller (cortex, medulla, and pyramids) structures. Findings indicated that translumbar ultrasonography is a valid method for measuring renal dimensions in horses.     

Estimation of the Rate of Egg Contamination from Salmonella‐Infected Chickens

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent causes for human gastroenteritis and is by far the predominant Salmonella serovar among human cases, followed by Salmonella Typhimurium. Contaminated eggs produced by infected laying hens are thought to be the main source of human infection with S. Enteritidis throughout the world. Although previous studies have looked at the proportion of infected eggs from infected flocks, there is still uncertainty over the rate at which infected birds produce contaminated eggs. The aim of this study was to estimate the rate at which infected birds produce contaminated egg shells and egg contents. Data were collected from two studies, consisting of 15 and 20 flocks, respectively. Faecal and environmental sampling and testing of ovaries/caeca from laying hens were carried out in parallel with (i) for the first study, testing 300 individual eggs, contents and shells together and (ii) for the second study, testing 4000 eggs in pools of six, with shells and contents tested separately. Bayesian methods were used to estimate the within‐flock prevalence of infection from the faecal and hen post‐mortem data, and this was related to the proportion of positive eggs. Results indicated a linear relationship between the rate of contamination of egg contents and the prevalence of infected chickens, but a nonlinear (quadratic) relationship between infection prevalence and the rate of egg shell contamination, with egg shell contamination occurring at a much higher rate than that of egg contents. There was also a significant difference in the rate of egg contamination between serovars, with S. Enteritidis causing a higher rate of contamination of egg contents and a lower rate of contamination of egg shells compared to non‐S. Enteritidis serovars. These results will be useful for risk assessments of human exposure to Salmonella‐contaminated eggs.     

Diagnosis of bovine spongiform encephalopathy: A review

Summary

Cows affected with bovine spongiform encephalopathy (BSE) display chronic neurological signs consisting of behavioural changes, abnormalities of posture and movement, and/or hyperaesthesia. At present, there are no laboratory test available to diagnose BSE in the live animal. In this article, we describe the post‐mortem diagnostic examination of brains from BSE‐suspected cattle as currently performed at ID‐Lelystad. The routine laboratory diagnosis of BSE consists of histopathological examination of the brain and detection of the modified prion protein, PrP^BSE, in brain tissue. These tests, however, have the disadvantage of being laborious and time consuming, so that results are available only after several days.

Recently, at ID‐Lelystad a new post‐mortem test has been developed that enables screening of larger volumes of brain samples for PrP^BSE within 1 day. This BSE test is especially suited for slaughterline monitoring. A preliminary validation study has shown that both sensitivity and specificity are 100% compared to the gold diagnostic standard of histopathology.     

Trypanosomiasis in Indonesia

Summary

This review describes research conducted from 1900–1983 on trypanosomiasis due to Trypanosoma evansi in Indonesia. Clinical signs and post‐mortem findings in horses, cattle, buffaloes, pigs and dogs, experimental transmission tests to establish possible surra vectors in Indonesia, and research on chemotherapy and chemoprophylaxis are discussed.     

Infection of Two Goatherds with Mycoplasma mycoides Subsp. capri in Hungary,Evidence of a Possible Faecal Excretion

During epidemic outbreaks in two goatherds clinical symptoms and deaths occurred in five (14%) of the 3‐week‐old goat kids in farm A, and in six (33%) of those in farm B. In the latter farm, three female goats aborted before the clinical symptoms in the kids emerged. Mycoplasma could be isolated from both healthy and sick goat kids and from female goats, which had diseased kids or had aborted. Three goat kids (one from herd A and two from herd B) were sent for post‐mortem examination. In all these cases septicaemia caused by Mycoplasma was diagnosed. Based on the bacteriological examination the Mycoplasma strains proved to be Mycoplasma mycoides subsp. capri (Mmc). This was confirmed by the PCR examination. Mmc was isolated from several locations includingfrom the rectum of one healthy female goat, and from two diseased kids. In addition, bacteria were detected in the small intestine in two of the necropsied kids by bacteriological and/or immunohistochemical methods. The finding suggests that Mmc may be transmitted via faeces in goatherds, kept under conventional conditions.     

Sensory evaluation of breast fillets from argon‐stunned and electrically‐stimulated broiler carcases processed under commercial conditions

1. A comparison of eating quality of breast meat (pectoralis major) filleted at 2 h post‐mortem was made between broilers stunned with argon‐induced anoxia (less than 2% residual oxygen) and broilers which were electrically‐stunned and their carcases electrically‐stimulated under commercial conditions.

2. Fifty breast muscles were filleted from the carcases of argon stunned broilers at 2 h post‐mortem. Fifty breast muscles were also removed at the same time from the carcases of broilers which were electrically‐stunned and electrically‐stimulated. A ‘control’ group of broilers which were electrically‐stunned and electrically‐stimulated and processed under as similar conditions as possible were also filleted after overnight ageing in the air chiller.

3. Sensory analysis was performed using 10 trained panelists, who were asked to rate the fillets on a 1 to 8 hedonic scale for taste, texture, juiciness and overall liking.

4. The mean ranks for texture and overall liking differed between the groups. The mean ranks based on texture were the highest for control, intermediate for argon stunning and the lowest for electrical stimulation treatment group. The mean ranks based on overall liking were similar for the control and argon stunning groups, and their ranks were higher than that of electrical stimulation treatment group. The mean ranks for taste and juiciness did not differ significantly between the groups.

5. It is concluded that, in comparison with electrical stimulation of broiler carcases soon after plucking, stunning broilers with argon‐induced anoxia produced tender breast meat when filleted at 2 h postmortem.     

Preselection of finishing pigs on the farm as an aid for meat inspection

Summary

The ability of pig suppliers to separate pigs with abnormalities from pigs without abnormalities at the end of the finishing period was investigated Nineteen hundred and seventy‐eight pigs, delivered by 22 pig suppliers, were involved in the experiment The pigs were inspected on the farm by the pig supplier and separately, by a veterinary expert The animals were sent in 22 deliveries to one slaughterhouse. A veterinary meat inspector carried out the ante‐ and post‐mortem inspections. The results of the inspections were compared The measure of agreement, Cohen's Kappa (CK), indicated a poor (CK < 0.40) to fair (0.40 < CK < 0.75) agreement among the results of the different inspection procedures, depending on the abnormality under investigation. There was a fair to good agreement for the abnormality ‘tail lesion’ among all inspections. Some findings of the live animal, such as ‘straggler’, were associated with a wide range of post‐mortem abnormalities. It is concluded that preselection is possible and that the economic and practical feasibility of preselection should be investigated.     

Tuberculosis caused by Mycobacterium bovis infection in a donkey

Mycobacterial infections are rare in equines. Mycobacterium bovis (M. bovis) is an important zoonotic bacterial pathogen causing disease in a wide range of animal species and sporadically causes severe disseminated disease in horses. This report describes the clinical, gross post‐mortem examination and histopathological findings in a case of disseminated M. bovis infection in a donkey which to the authors’ knowledge has not been previously documented in the scientific literature.