Gross pathology of herons and egrets (family Ardeidae) at a wildlife rehabilitation centre in Northern California

Gross necropsies were performed on all herons and egrets (family Ardeidae) that died or were euthanized at a wildlife rehabilitation centre in Fairfield, California, over a six-week period in the summer of 2018 (n = 145). Of the animals necropsied, 108 (74.5%) were euthanized and 37 (25.5%) died. Common reasons for euthanasia were trauma (n = 24), MBD (n = 39) and non-specific signs such as hypothermia and obtundation that persisted in the face of medical and supportive care (n = 32). MBD was found both in birds at admission (n = 9) and later in care (n = 34), despite calcium supplementation to correct calcium:phosphorus ratios of foods. Feeder fish were suspected to be deficient in vitamin D, and supplementation successfully reduced the development of this problem during the care later in the season. Nematodes of the genus Eustrongylides were found in the coelomic cavities of 43 (30%) birds. High burdens were often accompanied by coelomitis and abscessation involving internal organs. Visceral gout (n = 10) and intestinal perforation (n = 4) were both strongly associated with the administration of meloxicam. These findings suggest meloxicam should be used with caution in these species. Other less common findings included septic arthritis, intestinal perforation and hepatomegaly. This study describes common gross pathological findings of herons and egrets in a wildlife rehabilitation centre in California and demonstrates the utility of gross necropsies in determining cause of death when more advanced post-mortem diagnostics are unavailable

New species of Dispio Hartman, 1951 and Streblospio Webster, 1879 (Polychaeta, Spionidae) from the coast of the Iberian Peninsula

Re-assessment of spionid specimens from Iberian Peninsula initially assigned to Dispio uncinata Hartman, 1951 and Streblospio benedicti Webster, 1879 led to the recognition of two new species from the spionid genera Dispio and Streblospio from coasts around the Iberian Peninsula. Dispio elegans sp. nov. is characterised by having an oblanceolate-shaped prostomium. In addition, the first two notopodial postchaetal lamellae are serrated with digitiform papillae, the anterior neuropodial lamellae are smooth; all branchiae are almost completely fused to the notopodial lamellae, but with the tips free; the notochaetae on chaetiger 1 are smooth, alimbate capillaries; the ventral chaetae located in the position of the sabre chaetae on chaetigers 1–2 are smooth, alimbate capillaries, but becoming granulated on chaetiger 3; and the middle and posterior chaetigers are granulated and reticulated. Streblospio padventralis sp. nov. is characterized by lacking dorsal papillae between the branchiae of chaetiger 1; the hooks have 4–5 pairs of small teeth; sabre chaetae are present from chaetiger 3; the pygidium has two ventral lappets; and brooding structures are present in the coelomic cavities. We suggest raising the status of Streblospio benedicti japonica Imajima, 1990 to full species level as S. japonica Imajima, 1990. A key for Streblospio species is provided.

Gastric Cryptosporidiosis in Freshwater Angelfish (Pterophyllum Scalare)

A freshwater angelfish ( Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium.

Histological examination of the chaetognathan morphological structure in the region of a supposed trunk-tail septum

A histological examination was conducted based on sections done in series in transverse and longitudinal directions of Aidanosagitta macilenta (Sagittidae, Chaetognatha) in a region which includes the anterior parts of the testes and the posterior part of the ovaries. We found that, in mature individuals (the 4th stage of maturation), the anterior parts of the testes are located in front of the posterior part of the ovaries. The anterior parts of the testes have a ventral position adjoining the ventral muscular bands. The ovaries are located more dorsally than the testes at the level of lateral fi elds. A transverse trunk-tail septum between testes and ovaries was not revealed. These data support an idea that a structure which was earlier treated as a tail-trunk septum is actually the anterior edges of the testes. Both longitudinal coelomic cavities continue into the tail region without any transverse septa. The paired tail cavities as can be seen from their composition and functions represent the testes consisting of a peripheral compact portion with undifferentiated germ cells and a space where the maturation of cells occurs. The tail is distinguished anatomically as a post-anal portion of the body but it is not a true segment as it is not separated from a trunk part of the body by the trunk-tail septum. The body of Chaetognatha consists of two true parts (segments). A mesenterial septum divides the body longitudinally-symmetrically from a trunk-head septum down only to the caudal end of the gut. In the tail region there is a medial septum formed by the medial walls of testes. Gonads in both females and males do not have any duct connecting them with a gut cavity. The ovaries and the testes are covered by a coelomic lining and a duct between the ovaries and the testes is absent.

Occurrence of the lessepsian species Leonnates persicus (Polychaeta: Nereididae) in Izmir Bay, Aegean Sea

The recent establishment of the lessepsian species Leonnates persicus (Annelida: Polychaeta: Nereididae) in Izmir Bay (Aegean Sea) was investigated. A total of four specimens were collected at three stations in December 2001, with two specimens having eggs within their coelomic cavities and parapodia. A re-description of the species together with its ecological and distributional aspects are provided.

Morphometric partitioning of respiratory surfaces in amphioxus (Branchiostoma lanceolatum Pallas)

The anatomical diffusing factors (ADFs), defined as the ratio of surface area to the thickness of the diffusion barrier, of possible respiratory surfaces of adult amphioxus (Branchiostoma lanceolatum) were evaluated using stereological methods. The ADF is greatest for the lining of the atrium and for the skin covering the segmental muscles. Calculation of the diffusing capacities for O(2) revealed that the lining of the atrium makes up nearly 83 % of the entire diffusing capacity (8.86 × 10(−3) microl min(−1)mg(−1)kPa(−1) while the skin over the segmental muscles (9%), the skin over the metapleural fold (4%) and the gill bars (4%) are of minor importance. The diffusing capacity of surfaces lying over coelomic cavities makes up 76% of the whole diffusing capacity, which is consistent with the hypothesis that the coelom may function as a circulatory system for respiratory gases. Muscles have approximately 23% of the entire diffusing capacity, indicating that they may be self-sufficient for O(2) uptake. The diffusing capacity of the blood vessels in the gill bars is only 1% of the total. Thus, the ‘gills’ lack significant function as respiratory organs in amphioxus (lancelets).