Life history and social structure as drivers of persistent organic pollutant levels and stable isotopes in Hawaiian false killer whales (Pseudorca crassidens)

We examined the tooth ultra-structure of harbour porpoises (Phocoena phocoena) from Scottish waters to determine whether the incidence of mineralization anomalies could be related to certain life history events (e.g. the achievement of sexual maturation) as well as other factors that affect the general health of the individual (e.g. persistent organic pollutant (POP) concentrations in blubber). Five distinct types of mineralization anomalies were recorded: accessory lines, marker lines, dentinal resorption, cemental disturbance and pulp stones and the occurrence of these anomalies was scored by sex, age and maturity state. Overall, the incidence of mineralization anomalies was high and tended to increase with age. Marker lines and accessory lines were the most commonly recorded anomalies while pulp stones were least frequent. Duplicate teeth (i.e. from the same individual) always showed the same pattern of anomaly occurrence.Fitted binary generalized linear and additive models indicated that the presence of dentinal resorption, cemental disturbance and marker lines in harbour porpoise teeth increased with age, body length and maturity. Males displayed marker lines more frequently than females. Age was the best predictor of the incidence of dentinal resorption and cemental disturbance while age and sex were the best predictors of the incidence of marker lines. The time course of appearance of dentinal resorption and cemental disturbance suggests that their occurrence could be related to physiological stress linked to sexual maturation. Marker lines were found within growth layer groups which coincided with the beginning of weaning and sexual maturation, suggesting an association with these two major life history events. Accessory lines were found in most teeth and may be a normal characteristic of porpoise teeth or reflect regular events. Pulp stones appeared only in mature animals. We found no evidence that the presence of anomalies in teeth was significantly related to POP concentrations in the blubber.

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Using stable isotopes and C:N ratios to examine the life-history strategies and nutritional sources of larval lampreys

Journal of Fish Biology ◽

10.1111/jfb.12858 ◽

2015 ◽

Vol 88 (2) ◽

pp. 638-654 ◽

Cited By ~ 8

Author(s):

T. M. Evans ◽

J. E. Bauer

Keyword(s):

Stable Isotopes ◽

Life History ◽

Life History Strategies

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Gastrointestinal parasites and prey items from a mass stranding of false killer whales, Pseudorca crassidens, in Rio Grande do Sul, Southern Brazil

Revista Brasileira de Biologia ◽

10.1590/s0034-71082001000100008 ◽

2001 ◽

Vol 61 (1) ◽

pp. 55-61 ◽

Cited By ~ 11

Author(s):

A. L. V. ANDRADE ◽

M. C. PINEDO ◽

A. S. BARRETO

Keyword(s):

Rio Grande ◽

Gastrointestinal Parasites ◽

Southern Brazil ◽

Rio Grande Do Sul ◽

Ommastrephes Bartramii ◽

Killer Whales ◽

Food Items ◽

Pseudorca Crassidens ◽

Mass Stranding ◽

Prey Items

The gastrointestinal tract of 14 false killer whales, 6 males and 8 females, stranded in June 1995 in southern Brazil, with total standard lengths from 338 to 507 cm, were analysed for endoparasites and food items. A pregnant female had a male foetus of 77.5 cm. Parasites were found in all 14 false killer whales. The nematode Anisakis simplex (Rudolphi, 1809) was found in the stomach of 57% of the animals and the acanthocephalan Bolbosoma capitatum (Linstow, 1889) Porta, 1908 was present in the intestine of all specimens and showed densities up to 600 m-1. An unidentified cestode (Tethrabothridae) was found also in the intestines of 14% of the individuals. The high infections of B. capitatum and A. simplex were not directly related with the cause of death. In the stomachs of four females, beaks of at least eight specimens of the oceanic and epipelagic species Ommastrephes bartramii (Lesueur, 1821) were found, with mantle lengths ranging from 189.8 to 360.9 mm. The distribution of O. bartramii in the coast of Rio Grande do Sul is consistent with false killer whales feeding in continental shelf waters.

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Specialisation events of fungal metacommunities exposed to a persistent organic pollutant are suggestive of augmented pathogenic potential

Microbiome ◽

10.1186/s40168-018-0589-y ◽

2018 ◽

Vol 6 (1) ◽

Cited By ~ 2

Author(s):

Celso Martins ◽

Adélia Varela ◽

Céline C. Leclercq ◽

Oscar Núñez ◽

Tomáš Větrovský ◽

...

Keyword(s):

Organic Pollutant ◽

Persistent Organic Pollutant ◽

Pathogenic Potential

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A long post-reproductive lifespan is a shared trait among genetically distinct killer whale populations

10.22541/au.161460887.74001987/v1 ◽

2021 ◽

Author(s):

Mia Nielsen ◽

Samuel Ellis ◽

Jared Towers ◽

Thomas Doniol-Valcroze ◽

Daniel Franks ◽

...

Keyword(s):

Social Structure ◽

Killer Whale ◽

Demographic Data ◽

Reproductive Period ◽

Substantial Variation ◽

Killer Whales ◽

Reproductive Conflict ◽

Demographic Patterns ◽

General Prediction

The extended female post-reproductive lifespan found in humans and some toothed whales remains an evolutionary puzzle. Theory predicts demographic patterns resulting in increased female relatedness with age (kinship dynamics) can select for a prolonged post-reproductive lifespan due to the combined costs of inter-generational reproductive conflict and benefits of late-life helping. Here we test this prediction using >40 years of longitudinal demographic data from the sympatric yet genetically distinct killer whale ecotypes: resident and Bigg’s killer whales. The female relatedness with age is predicted to increase in both ecotypes, but with a less steep increase in Bigg’s due to their different social structure. Here, we show that there is a significant post-reproductive lifespan in both ecotypes with >30% of adult female years being lived as post-reproductive, supporting the general prediction that an increase in local relatedness with age predisposes the evolution of a post-reproductive lifespan. Differences in the magnitude of kinship dynamics however, did not influence the timing or duration of the post-reproductive lifespan with females in both ecotypes terminating reproduction before their mid-40s followed by an expected post-reproductive period of ~20 years. Our results highlight the important role of kinship dynamics in the evolution of a long post-reproductive lifespan in long-lived mammals, while further implying that the timing of menopause may be a robust trait that is persistent despite substantial variation in demographic patterns among population.

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