Chironomid mouthpart deformities as indicator of environmental quality: a case study in Lake Trasimeno (Italy).

The aim of the present study was to monitor mouthpart deformities of Chironomus plumosus (Insecta-Diptera) in Lake Trasimeno (2000-2010) in relation with sediment contamination by heavy metals, which is one of the main causes of deformity induction. In Lake Trasimeno, concentrations of heavy metals in the investigated littoral zone were low, in comparison with those of the central area. By contrast, the incidence of deformities was much higher in the littoral station (2006-2009) than in the central area. In the littoral zone, the deformities progressively decreased and by 2010 reached values similar to those observed in the central area (2000-2002, 2010). This decrease was mainly due to the reduction of severe deformities, thus indicating an environmental quality recovery of this littoral sector. Chemical analysis revealed that the higher incidence of deformities in the littoral zone was not caused by heavy metal contamination, unless they may have contributed to a joint action with other toxicants. The present study on Lake Trasimeno provided additional evidence that chironomid mouthpart deformities can be used in biomonitoring programs to evaluate sediment contamination by toxicants. Since mouthpart deformities may also be induced by compounds not included in routine chemical analyses, they may better reflect sediment quality than chemical analysis alone.

Injuries and deformities in fish: their potential impacts upon aquacultural production and welfare.

Fish can be the recipients of numerous injuries that are potentially deleterious to aquacultural production performance and welfare. This review will employ a systematic approach that classifies injuries in relation to specific anatomical areas of the fish and will evaluate the effects of injury upon production and welfare. The selected areas include the (1) mouth, (2) eye, (3) epidermis and (4) fins. These areas cover a large number of external anatomical features that can be injured during aquacultural procedures and husbandry practices. In particular, these injuries can be diagnosed on live fish, in a farm environment. For each anatomical feature, this review addresses (a) its structure and function and (b) defines key injuries that can affect the fish from a production and a welfare perspective. Particular attention is then given to (c) defining known and potential aquacultural risk factors before (d) identifying and outlining potential short- and long-term farming practices and mitigation strategies to reduce the incidence and prevalence of these injuries. The review then concludes with an analysis of potential synergies between risk factors the type of injury, in addition to identifying potential synergies in mitigation strategies. The paper covers both aquaculture and capture-based aquaculture.

Gelatinous marrow transformation and hematopoietic atrophy in a miniature horse stallion.

Gelatinous marrow transformation, or serous atrophy of bone marrow fat, has been noted in livestock, laboratory animals, and wildlife in association with an inadequate plane of nutrition, inanition, or intoxication. This is a report of gelatinous marrow transformation and hematopoietic marrow atrophy in a 5-year-old miniature horse stallion. The horse had oral malformations leading to poor food assimilation and emaciation. A bone marrow biopsy obtained to investigate persistent anemia and leukopenia showed hematopoietic atrophy and replacement of fat with a granular extracellular substance, which stained with alcian blue, consistent with acidic mucopolysaccharide content. Surgical correction of the dental abnormalities resulted in improved food assimilation, weight gain, and resolution of cytopenias. In humans, gelatinous bone marrow transformation and hematopoietic atrophy are commonly associated with malnutrition from anorexia nervosa and other causes. The cause of hematopoietic atrophy is unknown but may relate to a nonsupportive marrow microenvironment and inadequate hematopoietic substrate availability. Similar pathogenic mechanisms were suspected in this horse.

The use of a genetic-counselling program by Dutch breeders for four hereditary health problems in boxer dogs.

Our group developed a genetic-counselling program for boxer-dog breeders in The Netherlands, using data for cryptorchidism (uni- and/or bilateral), epilepsy, knee-problems (including ligament rupture, fractured or ruptured meniscus, severe osteo-arthrosis of the knee, or a combination of these disorders), and schisis (including cheiloschisis, palatoschisis, or cheilopalatoschisis). We transformed the estimated breeding values (EBVs) into odds ratios (ORs), to enable the breeder to compare the risk for each of the traits for a certain dam-sire combination with the average population risk (set at 1). The goal of the study was to evaluate the use of our genetic-counselling program by Dutch breeders of boxer dogs. We asked breeders of the Dutch Boxer Club to send in an application form for genetic-counselling from June 1 to December 1, 2000. Breeders indicated on this application form three desirable sires for their dam (sire 1, sire 2, sire 3) in random order. On the basis of this information, a counselling report was produced which included ORs for the four diseases in litters of the dam-sire combinations indicated on the application form. Together with the counselling report, the breeders received an evaluation form. We received 129 application forms from 70 breeders, and collected 125 evaluations. Of these evaluations, 96 were informative about the influence of the counselling report on sire choice. The most-important criteria used by breeders to select sires were: the exterior characteristics (60%) and known progeny (52%). Although it was the first time breeders could make use of genetic-counselling, 32% of the breeders indicated that the genetic-counselling played a major role in their sire selection. Breeders expressed little difference in importance for the four genetic traits, but there was a tendency to consider epilepsy more than the others. Breeders hesitated to put long-term population interest above short-term personal interest. Nevertheless, the general conclusion of this study is that breeders acknowledge the value of counselling, especially to reduce the frequency of a threatening disease such as epilepsy.

Chironomidae (Diptera, Nematocera) fauna in three small streams of Skania, Sweden.

Two unpolluted streams and one chemically and thermally polluted stream in Skania, Sweden, were investigated in summer 1995 for their temporary chironomid fauna and the occurrence of buccal deformities. The unpolluted streams 'Ovedsan' and 'Skäralidbäcken' each contained, respectively, 13 and 16 taxa, with a dominance of Microtendipes pedellus group and Micropsectra spp., respectively. Most taxa were found in the pebbles and the submerged vegetation. Deformities were insignificant. The degraded stream Ybbarpsan in Perstorp contained 5 taxa, dominated by Procladius choreus. This species had 14% deformed larvae, interpreted as an effect of the chemical pollution. Shannon H and equitability J reflected the differences in chironomid community structure between the two unpolluted and the polluted sites. The Belgian Biotic Index scored maximally '10' in Skäralid, however only '6' in Oved and '5' in Perstorp. The combination of rapid assessment of macrobenthos and description of communities of Chironomidae, with mention of deformed larvae, adds a bonus of information about the temporary state of a stream.

Exposure to 17 alpha-ethinylestradiol and bisphenol A--effects on larval moulting and mouthpart structure of Chironomus riparius.

The effects of the endocrine-disrupting chemicals 17alpha-ethinylestradiol (EE) and bisphenol A (BPA) on the development of the aquatic life-cycle stages (eggs to pupa) of Chironomus riparius were investigated. The test species was exposed to sublethal concentrations of EE and BPA (10 ng/L-1mg/L) and effects on larval weight and moulting success were recorded. In addition, three mouthpart structures (mentum, mandibles, and pecten epipharyngis) present on the head capsules of fourth-instar larvae were examined for structural deformities. Moulting was delayed and larval wet weight significantly reduced (P<0.05) at the highest treatment concentration (1mg/L) of both chemicals. No significant effect on either of these parameters was noted in the remaining treatments. However, deformities in the mouthparts of C. riparius were observed at very low exposure concentrations (10 ng/L), although the incidence of deformities was greater in the chironomids exposed to EE than BPA. Effects were mainly associated with the mentum, with statistically significant differences in median deformity score (Kruskal-Wallis P<0.001) recorded for both chemicals. At similar effect concentrations, an increased percentage of exposed animals had deformities of the pecten epipharyngis; however, little evidence of deformity was noted for the mandibles. At high concentrations, where moulting and wet weight were affected, no incidence of mouthpart deformity was noted. The relevance of these results in relation to the identification of an "endocrine-sensitive" endpoint for invertebrates is discussed.

Mouthpart deformities and community composition of Chironomidae (Diptera) larvae downstream of metal mines in New Brunswick, Canada.

The effect of metal enrichment on chironomid communities was examined in streams receiving mine drainage from metal mining operations in New Brunswick, Canada. At five sites receiving mine drainage, metal concentrations were significantly (p < 0.05) elevated in water (Zn), periphyton (Cd, Co, Cu, and Zn), and chironomid tissue (Cu, Cd, and Zn) relative to five paired reference locations. Metal concentrations in chironomid larvae were significantly correlated with concentrations in both water and periphyton. Chironomid communities were severely affected at sites receiving mine drainage as demonstrated by reduced genera richness and altered community composition. Sites receiving mine drainage exhibited an increased abundance of metal-tolerant Orthocladiinae and a reduced abundance of metal-sensitive Tanytarsini relative to reference sites. The incidence of mentum deformities was significantly elevated at sites receiving mine drainage (1.43 +/- 0.24%), with the mean percentage approaching a doubling of that observed at reference sites (0.79 +/- 0.22%). Trace metal concentrations at mine-associated streams in New Brunswick significantly affected the benthic community and have the potential to alter the structure and function of these aquatic ecosystems.

The use of chironomid deformation in an in situ test for sediment toxicity.

An in situ bioassay using mouthpart deformities in Chironomus riparius larvae was developed to monitor sediment toxicity. Second-instar larvae, along with a standardized amount of food and sediment taken from the study locations, were enclosed in cages that were placed on the sediment surface of rivers. Mouthpart deformities were screened after larval molting to the fourth instar (exposure time: 7-10 days). Mouthpart deformities of caged and field larvae (when present) were related to the estimated sediment toxicity. By summing toxicant concentrations and normalizing them to the organic matter and clay contents, a significant relationship between toxicity levels and mouthpart deformities in the mentum was revealed. Results suggest that the pattern of observed deformities was indicative of site toxicity rather than a characteristic of the laboratory larval population used. The main advantage of the proposed in situ bioassay is the possibility to assess the incidence of deformities at sites where C. riparius does not occur naturally.

A distinct Mendelian autosomal recessive syndrome involving the association of anotia, palate agenesis, bifid tongue, and polydactyly in the dog.

A presumed genetic syndrome is described in a family of St. Bernards. Four identically affected littermates presented the association of palate agenesis, anotia, incomplete bifid tongue, preaxial hind paw polydactyly, and an extra thoracic vertebra and rib. Pedigree analysis is compatible with an autosomal recessive gene.

[Oral cavity diverticulum in a deer. Case report]. / Mundhöhlendivertikel bei einem Hirsch. Fallbericht.

The paper describes a deer with sacculation of the oral cavity floor. The diverticulum had no influence on ingestion and physical development.

Oral diseases and veterinary dentistry.

Oropharyngeal disease is common in dogs and cats. Signs are seldom apparent to the owner until the disease is well advanced, and often are not specific for a particular disease. Signs include inappetence, pawing at the mouth, drooling of saliva, dysphagia, and halitosis. These signs can result from primary oral disease, or from effects of systemic or skin disease. Oral examination requires a cooperative patient; sedation may be necessary so that the entire oral cavity can be examined without causing the animal pain or risking injury to the examiner.