Time and energy constraints in pinniped lactation

Previous reviews have recognized patterns of lactation in pinnipeds divided along phylogenetic lines. This study extended previous models of lactation in pinnipeds by explicitly taking into account all the energetic costs to mothers. Based on an analysis of time-energy budgets, the feasible lactation strategy for a species can be shown to depend on body mass. Due to increased metabolic costs of maintenance, species with a large body mass cannot normally sustain lactation by foraging during lactation unless they have access to rich local prey resources. Consequently, large pinnipeds must normally sustain lactation from body reserves. This disadvantage is compensated in large pinnipeds by freedom to forage in support of offspring at greater range whereas small pinnipeds are restricted to foraging within the locality of the pupping colony. In the absence of correlations between major life-history variables and body mass in pinnipeds, the principal patterns of lactation are likely to be different solutions to the trade-off between foraging on a relatively rich prey resource at long range and foraging on a poorer prey resource within a restricted range. Hence phylogeny may be less important than adaptation in the evolution of pinniped lactation.     

CHEMICAL RESTRAINT AND ANESTHESIA OF PINNIPEDS: A REVIEW

Drugs used to restrain and anesthetize pinnipeds have included neuromuscular blocking agents, narcotic analgesics, barbiturates, cyclohexamines, ataractics and inhalational agents. Problems associated with narrow margins of safety, thermoregulatory disturbances, cardiovascular changes and fatalities have excluded all but the cyclohexamines, ataractics and inhalational agents from presently accepted drugs for chemical restraint and anesthesia of pinnipeds. Combinations of tiletamine hydrochloride and zolazepam hydrochloride show great promise for immobilizing some species of pinnipeds in the field and inhalational agents are recommended for surgical anesthesia.     

A MORPHOLOGICAL CONSIDERATION OF THE RELATIONSHIPS OF PINNIPEDS TO OTHER CARNIVORANS BASED ON THE BONY TENTORIUM AND BONY FALX

The close relationships of pinnipeds to other carnivorans were studied based on morphological characteristics of the bony tentorium (BT) and bony falx (BF) of carnivorans. It appears to be an important characteristic of the Carnivora that the clear BT is present in almost all species including pinnipeds. The BF is present in all species of pinnipeds, and only in the genus Ursus among fissipeds observed.
The parietal bone of all otariids and odobenids observed shows an extremely characteristic form as compared with other carnivorans. The sagittal and squa-mous borders of the parietal bone of these groups are bridged by a thin bony plate which forms large portions of the BT and BF. In phocids, the aspects of the BT and BF vary among species, but are apparently distinct from those of otariids and odobenids.
The BT of carnivorans can be divided into four types which appear to be useful for classification of the Carnivora. On the basis of the BT and BF form, the Otariidae and Odobenidae appear to have a specific sister relationship to the Ursidae, while the Phocidae appears to have dose affinities to the Mustelidae. Morphological differences of the BT and BF among pinnipeds strongly support the diphyletic origin of pinnipeds.     

UNDERSTANDING AND INTERPRETING HEMATOCRIT MEASUREMENTS IN PINNIPEDS

Hematocrit data are relatively easily obtained from blood samples of pinnipeds but differences in methodology and variable physiological conditions of the subjects can significantly alter their values. This two-fold problem makes comparative data and modeling efforts difficult. To quantify the difficulty of obtaining accurate and representative hematocrit values in pinnipeds, hematocrit was measured by both microcentrifugation and Coulter counter methods in a range of pinnipeds under a variety of physiological and handling conditions. The data show that the Coulter counter hematocrit values were 4%-15% higher than those measured by microcentrifugation. In addition, blood samples from restrained animals showed consistently elevated hematocrit values relative to resting subjects. A significant difference was also found between hematocrit values from pups and adults. Finally, hematocrit was shown to decline over the course of isofluorane anesthesia. Taken together, these results suggest that laboratory methodology, developmental state, and animal handling techniques can significantly alter hematocrit values in pinnipeds. Thus, modeling efforts that require representative hematocrit values, such as calculations of total blood oxygen stores, can be markedly impacted by variations in hematocrit measurement techniques and sampling regimes.     

FLIPPERS AND PINNIPED PHYLOGENY: HAS THE PROBLEM OF CONVERGENCE BEEN OVERRATED?

The phylogenetic relationships of the major groups of pinnipeds are of longstanding controversy. According to prevailing paleontological opinion, pinnipeds comprise two distinct lineages of independent terrestrial carnivoran origin, A logical correlate of this view is that an enormous degree of convergence accounts for the striking resemblances of these groups.
It has been generally supposed that derived similarities common to pinnipeds are independently acquired adaptations to a highly constraining environment. This has not been adequately substantiated. Moreover, considerable evidence favors a contrary conclusion. Acceptance of convergence necessarily rests on demonstration that taxa possessing characters suspected to be convergent are in fact not mutal nearest allies. In the absence of such phylogenetic information, shared derived characters are indicative of common ancestry irrespective of whether they are deemed "functionally important." Given meager support for the proposition that pinnipeds are related to different terrestrial lineages, it is currently more judicious to regard the group's origin as monophyletic. In addition to the presumed prevalence of convergence, biogeography, the high degree of morphological divergence of phocids, and the aberrant nature of phocines have improperly contributed to acceptance of independent pinniped origins.     

Surfactant from diving aquatic mammals.

Diving mammals that descend to depths of 50-70 m or greater fully collapse the gas exchanging portions of their lungs and then reexpand these areas with ascent. To investigate whether these animals may have evolved a uniquely developed surfactant system to facilitate repetitive alveolar collapse and expansion, we have analyzed surfactant in bronchoalveolar lavage fluid (BAL) obtained from nine pinnipeds and from pigs and humans. In contrast to BAL from terrestrial mammals, BAL from pinnipeds has a higher concentration of phospholipid and relatively more fluidic phosphatidylcholine molecular species, perhaps to facilitate rapid spreading during alveolar reexpansion. Normalized concentrations of hydrophobic surfactant proteins B and C were not significantly different among pinnipeds and terrestrial mammals by immunologic assay, but separation of proteins by gel electrophoresis indicated a greater content of surfactant protein B in elephant seal surfactant than in human surfactant. Remarkably, surfactant from the deepest diving pinnipeds produced moderately elevated in vitro minimum surface tension measurements, a finding not explained by the presence of protein or neutral lipid inhibitors. Further study of the composition and function of pinniped surfactants may contribute to the design of optimized therapeutic surfactants.     

Reproductive and Foraging Energetics of High Latitude Penguins, Albatrosses and Pinnipeds: Implications for Life History Patterns

Pinnipeds and seabirds feed at sea, but are tied to shore torear their young. Such a fundamental life history constraintshould lead to convergent adaptations in foraging and reproductiveecology. However, intrinsic differences in mammalian and avianreproductive biology may limitthe potential for convergence.In this paper I examine both reproductive and foraging energeticsof pinnipeds and seabirds. This is done in an attempt to identifytraits that might be considered convergent adaptations to lifein the marine environment and to show how divergent life historypatterns are optimal for different reasons. From this analysiswe find that seabirds invest a greater total amount of energyand protein into the offspring than pinnipeds, but this comesat the cost of making more trips to sea. Whereas pinnipeds foragein a manner more consistent with the predictions of centralplace foraging theory and exhibit a greater ability to compensateto the shortened breeding season typical of high latitude environments.     

Serodiagnosis of Mycoses Using Recombinant Antigens

The early diagnosis of mycoses is important for the institution of an effective antifungal therapy. Detection of antibodies against crude antigenic extracts is one of the standard techniques for the diagnosis of most mycoses. However, while these crude antigenic extracts are relatively easy to obtain, they usually show low reproducibility and are not very specific, since antibodies from patients with different mycoses may show cross-reactivity. The application of molecular biology techniques to the study of fungal antigens has allowed the production of recombinant antigens that may help to solve these problems. The purpose of this review is to discuss the use of recombinant fungal antigens in the diagnosis of mycoses.     

The mating systems of pinnipeds and marine iguanas: convergent evolution of polygyny

The convergent polygynous mating systems of marine iguanas and otariid pinnipeds depend on the existence of large female aggregations. These can build up where abundant marine food resources occur around oceanic islands which harbour fewer predators than continental areas. For marine iguanas distribution of food resources appears to determine the location of colonies, while for pinnipeds habitat choice is more decisive. In marine iguanas females benefit from gregariousness through reduced predation risk and social thermoregulation. In pinnipeds, sea lions may derive thermoregulatory benefits from gregariousness, while fur seals appear to be largely non-gregarious. In both groups males defend territories in areas of high female density. Large sexual size dimorphism presumably evolved in response to strong selection for high fighting potential of males. The capability to fast for prolonged periods of territory tenure is considered a secondary benefit of large male size, but not the driving force behind its evolution. We hypothesize that marginal males, through continuous sexual harassment of females that stay outside territories, have exerted pressure towards the evolution of female gregariousness.     

The evolution of aquatic feeding in seals: insights from Enaliarctos (Carnivora: Pinnipedimorpha), the oldest known seal

The development of pierce‐feeding and loss of oral processing represented major adaptations for underwater feeding in marine mammals. We examined the evolution of pierce‐feeding and its association with changes in tooth spacing and tooth size to determine whether pierce‐feeding was practiced by the earliest known pinnipeds. Data on crown size and spacing in postcanine dentition were collected and 1) analysed by principal components analysis (PCA) to determine the tooth morphospace of arctoid carnivores, 2) analysed by least squares (LS) regression and phylogenetic independent contrasts (PIC) to determine what morphological variables were associated with increases in tooth spacing, and 3) used to reconstruct the evolution of feeding related traits within a phylogenetic context. The PCA analysis revealed that within arctoid carnivores, the greatest differences in morphospace were associated with pierce‐feeding, and the early‐diverging seal Enaliarctos was placed within the pinniped morphospace. Increased tooth spacing within Pinnipedia is a result of decreased postcanine crown size. When the evolution of dental characters is reconstructed, ‘enaliarctines’ were found to represent an intermediate stage in evolution between ‘fissiped’ and pinniped carnivores. They retained the limited tooth spacing of terrestrial carnivores, possessed postcanine crown lengths intermediate in size between pinnipeds and fissipeds, and possessed reduced heterodonty characteristic of crown pinnipeds. Our study indicated that pierce‐feeding evolved early within pinnipeds. This suggested either that pierce‐feeding evolved prior to the loss of mastication, or that pierce‐feeding evolved at the same time as loss of mastication, and well before simplification of the dentition was completed.     

ARE PINNIPEDS FUNCTIONALLY DIFFERENT FROM FISSIPED CARNIVORES? THE IMPORTANCE OF PHYLOGENETIC COMPARATIVE ANALYSES

Abstract.— It is widely assumed that adaptations to an aquatic lifestyle are so profound as to produce only obvious differences between pinnipeds and the remaining, largely terrestrial carnivore species ("fissipeds"). Thus, comparative studies of the order Carnivora routinely examine these groups independently. This approach is invalid for two reasons. First, fissipeds are a paraphyletic assemblage, which raises the general issue of when it is appropriate to ignore monophyly as a criterion for inclusion in comparative studies. Second, the claim that most functional characters (beyond a few undoubted characteristic features) are different in pinnipeds and fissipeds has never been quantitatively examined, nor with phylogenetic comparative methods. We test for possible differences between these two groups in relation to 20 morphological, life-history, physiological, and ecological variables. Comparisons employed the method of independent contrasts based on a complete and dated species-level phylogeny of the extant Carnivora. Pinnipeds differ from fissipeds only through evolutionary grade shifts in a limited number of life-history traits: litter weight (vs. gestation length), birth weight, and age of eyes opening (both vs. size). Otherwise, pinnipeds display the same rate of evolution as phylogenetically equivalent fissiped taxa for all variables. Overall functional differences between pinnipeds and fissipeds appear to have been overstated and may be no greater than those among major fissiped groups. Recognition of this fact should lead to a more complete understanding of carnivore biology as a whole through more unified comparative tests. Comparative studies that do not include monophyletic groups for phylogenetically based comparative tests should be reconsidered.     

Baculum length and copulatory behaviour in carnivores and pinnipeds (Grand Order Ferae)

Relationships between baculum length, body weight and copulatory behaviour were examined in 66 species of carnivores and pinnipeds (Grand Order Ferae). Elongated bacula occur in most carnivore species of the families Ursidae, Canidae, Procyonidae and Mustelidae as well as in all pinnipeds studied. By contrast, members of the family Felidae have short bacula in relation to their body weights. Elongate bacula are found in carnivores and pinnipeds with a prolonged single intromission (PI) copulatory pattern. This finding agrees with results of a previous study of baculum length and PI copulatory patterns in primates. The enlarged baculum may serve to strengthen the penis and protect the urethra during prolonged intromissions. The distal pole of the baculum may also assist sperm transport since in some species it projects beyond the tip of the penis and probably contacts the female's os cervix during copulation. It is possible that stimulation of the female's genitalia by the baculum might also be important in mammals which are induced ovulators (e.g. Mustelidae). However, it is notable that elongation of the baculum has also occurred in some groups where females ovulate spontaneously (e.g. Canidae, Primates).     

Comparative assessment of amphibious hearing in pinnipeds

Auditory sensitivity in pinnipeds is influenced by the need to balance efficient sound detection in two vastly different physical environments. Previous comparisons between aerial and underwater hearing capabilities have considered media-dependent differences relative to auditory anatomy, acoustic communication, ecology, and amphibious life history. New data for several species, including recently published audiograms and previously unreported measurements obtained in quiet conditions, necessitate a re-evaluation of amphibious hearing in pinnipeds. Several findings related to underwater hearing are consistent with earlier assessments, including an expanded frequency range of best hearing in true seals that spans at least six octaves. The most notable new results indicate markedly better aerial sensitivity in two seals (Phoca vitulina and Mirounga angustirostris) and one sea lion (Zalophus californianus), likely attributable to improved ambient noise control in test enclosures. An updated comparative analysis alters conventional views and demonstrates that these amphibious pinnipeds have not necessarily sacrificed aerial hearing capabilities in favor of enhanced underwater sound reception. Despite possessing underwater hearing that is nearly as sensitive as fully aquatic cetaceans and sirenians, many seals and sea lions have retained acute aerial hearing capabilities rivaling those of terrestrial carnivores.     

Prevalence of pulmonary mycoses in smear-negative patients with suspected tuberculosis in the Brazilian Amazon

BackgroundPulmonary mycoses resemble clinically and radiologically chronic pulmonary tuberculosis. Studies describing the prevalence, etiology and clinical features of pulmonary mycosis are of crucial importance in the Brazilian Amazon.AimsTo estimate the frequency of pulmonary mycoses in smear-negative tuberculosis patients; to describe their demographic, epidemiological, and clinical characteristics; and to evaluate diagnostic methods.MethodsA cross-sectional study was conducted at two tuberculosis reference institutions in Amazonas, Brazil. We included 213 patients and collected clinical data, blood and induced sputum to perform serological, direct microscopy, microbiologic culture and PCR-based assays to identify infections caused by Aspergillus fumigatus, Paracoccidioides brasiliensis, Histoplasma capsulatum, Cryptococcus, and HIV. Chest computed tomography was also performed.ResultsPulmonary mycoses were diagnosed in 7% (15/213) of the cases, comprising ten aspergillosis cases, three cases of paracoccidioidomycosis and one case each of histoplasmosis and cryptococcosis. Among the patients with pulmonary mycoses, 86.7% were former tuberculosis patients. The most significant clinical characteristics associated with pulmonary mycoses were cavity-shaped lung injuries, prolonged chronic cough and hemoptysis.ConclusionsOur study confirmed the high prevalence of pulmonary mycoses in smear-negative tuberculosis patients in the Brazilian Amazon.     

Las micosis en Venezuela: casuística de los Grupos de Trabajo en Micología (1984-2010)

BackgroundIn 1984 the Venezuelan Work Groups in Mycology (VWGM) were created introducing an innovative approach to the study of the mycoses in Venezuela.AimTo study the occurrence of the mycoses in Venezuela.MethodsReview the reported cases of mycoses by the newsletter Boletín Informativo Las Micosis en Venezuela (VWGM) from 1984 to 2010.ResultsThe data collected showed 36,968 reported cases of superficial mycoses, 1,989 of deep systemic cases, and 822 of localized mycoses. Pityriasis dermatophytosis was the most common superficial infection, and paracoccidioidomycosis and histoplasmosis the most frequent deep systemic infection. Chromoblastomycosis was the most frequently diagnosed subcutaneous infection. The data provided showed the distribution by geographical area for each of the fungal infections studied, which may help to establish the endemic areas.DiscussionSuperficial mycosis is a public health problem due to its high morbidity and is probably responsible for some of the outbreaks in high-risk groups. Paracoccidioidomycosis and histoplasmosis were reported more often, which agrees with earlier reports prior to the formation of the VWGM. Cases of sporotrichosis and chromoblastomycosis in Venezuela can be considered unique due to the high number of cases. This study highlights the contribution of the VWGM to the behavior of the mycoses in Venezuela, its incidence, prevalence, and the recognition of these infections as a problem of public health importance. The VWGM should keep working in this endeavor, not only reporting new cases, but also unifying the clinical and epidemiological criteria, in order to properly monitor the evolving epidemiological changes reported in these types of infections.     

Pinnipeds or sirenians at western Indian Ocean Islands?

Records of pinnipeds and sirenians are rare in the western Indian Ocean away from continental coasts. In the case of pinnipeds there are apparently no records at all in this area, except for occasional stray Elephant seals Mirounga leonina as far north as Mauritius and Rodriguez, and a single record of an undetermined species in the southern Maldive Islands: the Indian Ocean now lacks any counterpart of the Monk seals of the Caribbean and the Pacific (King, 1956, 1964). In the case of sirenians, Dugongs are widely distributed round the continental coasts of the Indian Ocean, including Madagascar, the Comoros, and Ceylon, but there is much less information concerning them on more remote Indian Ocean islands. This paper draws attention to hitherto unnoticed reports of animals which could be either pinnipeds or sirenians made by 18th and early 19th century navigators, and reviews some of the published evidence for the existence of these animals in the 17th and 18th centuries in the Mascarene Islands. It is shown that many of the reef islands of the tropical western Indian Ocean were formerly inhabited by seals, of undetermined species and now extinct, and that some of the early references to Dugongs in fact concerned seals.     

Photodynamic Therapy in the Treatment of Superficial Mycoses: An Evidence-based Evaluation

Photodynamic therapy (PDT) is effective in the destruction of fungi. In order to evaluate the efficacy and safety of PDT for superficial mycoses, we performed an evidence-based review of published literature. Database of MEDLINE, EMBASE, and Cochrane Library was searched until March 2010. English-language articles evaluating the efficacy and safety of PDT for superficial mycoses were included. No randomized clinical trials were found. Seven reports described the antifungal effect of PDT against 63 superficial mycoses patients. Eight of 10 (80%) tinea cruris patients and 6 of 10 (60%) tinea pedis were led to mycological cure after 1–3 treatments. Unfortunately, only 4 (40%) tinea cruris patients and 3 (30%) tinea pedis had a persist healing at the 8-week follow-up. Six of the 9 (66.7%) foot-interdigital mycoses patients recovered clinically and microbiologically after 1 or 4 treatments. Only 2 patients (22.2%) had a persist healing at the 8-week follow-up. Eleven of 30 (36.6%) onychomycosis patients were cure for 18 months after treatment, and 3 onychomycosis patients were all cure in other 2 reports. The therapeutic effect of PDT for one pityriasis versicolor patients was well. Overall tolerability of PDT was good. Therefore, it is unclear what PDT’s place for superficial mycoses will be. Further clinical trials are needed to evaluate the efficacy of PDT to treat superficial mycoses. It is also important to optimize treatment protocols in order to cope with recurrence.     

Aspectos actuales de las enfermedades invasivas por hongos filamentosos

Invasive fungal infections have become a major cause of morbimortality in intensive care patients, persons suffering from cancer or immune deficiencies, and other diseases with impaired immunity. Candida albicans remains the most frequent fungal pathogen, but advances in the diagnosis, prevention and treatment of invasive candidiasis are leading to important etiological changes. Among the emerging invasive mycoses, are those caused by filamentous fungi, such as Aspergillus, Lomentospora/Scedosporium, Fusarium or the Mucorales. Invasive aspergillosis is difficult to diagnose, and although there are diagnostic tools available, their use is not widespread, and their effectiveness vary depending on the group of patients. Clinical suspicion in high-risk patients, radiological diagnosis and the use of biomarkers, such as 1,3-β-D-glucan and galactomannan, can be of great help. However, diagnostic resources are limited in other mycoses, but radiology, pathological studies and the microbiological diagnosis can be useful. The high mortality of these mycoses requires early empirical antifungal treatment in many cases. Voriconazole is the first choice for treatment of the majority of aspergillosis, scedosporiasis, fusariosis and other hyalohyphomycoses. The treatment of mucormycoses, Lomentospora prolificans infections or mycoses by dematiaceous fungi are more complicated. Amphotericin B is active against many mucoralean fungi, but the combination of two or more antifungal agents could be a therapeutic alternative in many amphotericin B-refractory mycoses. Current clinical challenges include improving the diagnosis and the treatment of these mycoses, along with improving the adequate prevention in patients at high risk of suffering from them.     

Cope's rule and the evolution of body size in Pinnipedimorpha (Mammalia: Carnivora)

Cope's rule describes the evolutionary trend for animal lineages to increase in body size over time. In this study, we tested the validity of Cope's rule for a marine mammal clade, the Pinnipedimorpha, which includes the extinct Desmatophocidae, and extant Phocidae (earless seals), Otariidae (fur seals and sea lions), and Odobenidae (walruses). We tested for the presence of Cope's rule by compiling a large dataset of body size data for extant and fossil pinnipeds and then examined how body size evolved through time. We found that there was a positive relationship between geologic age and body size. However, this trend is the result of differences between early assemblages of small-bodied pinnipeds (Oligocene to early Miocene) and later assemblages (middle Miocene to Pliocene) for which species exhibited greater size diversity. No significant differences were found between the number of increases or decreases in body size within Pinnipedimorpha or within specific pinniped clades. This suggests that the pinniped body size increase was driven by passive diversification into vacant niche space, with the common ancestor of Pinnipedimorpha occurring near the minimum adult body size possible for a marine mammal. Based upon the above results, the evolutionary history of pinnipeds does not follow Cope's rule.