The reproductive morphology and larval development in Spionidae has been dealt with extensively by Soderström (1920), Hannerz (1956), Orrhage (1964). Simon (1967), Blake (1969) and Rice (1980). The family shows a considerable variation in gamete morphology, modes of sperm transfer and types of larval development. One might also expect variability in features of the life history patterns, such as the life span, reproductive age, reproductive cycles and fecundity, both between and within species.Previous population studies on spionids include the work on populations of Polydora ciliata (Johnston) (Dorsett, 1961); (Daro & Polk, 1973), on populations of Scolelepis squamata (Müller) (Joyner, 1962); (Richards, 1970), on a population of Scolecolepides viridis (Verrill) (George, 1966) and on a laboratory reared population of Malacoceros cf. fuliginosus (Guérin, 1973). The present paper is an attempt to analyse the patterns of life history as they appear in littoral populations of Spio martinensis Mesnil, Polydora ciliata (Johnston), Pygospio elegans Claparede and Malacoceros fuliginosus (Claparède) at localities in N. E. England. The main features considered here are the changes in the size (age) distributions, the annual cycles of reproduction, the output of offspring and population density changes.The Spio species in the population at Black Middens, North Shields, which is referred to S. martinensis Mesnil (1896) in this paper, was previously referred to S. filicornis (Müller, 1776) by Brady (1943). This species is identical to Mesnil's species, both in morphology and with regard to known biological features, while S. filicornis differs from it morphologically and its distribution pattern (Hannerz, 1956; Rasmussen, 1973; Wolff, 1973, Gudmundsson, in preparation).
Background Feelings of loneliness and social isolation are common among the elderly, affecting both health and wellbeing. The COVID-19 pandemic has altered social connections through health precautions, restrictions and other factors. However, limited research has been conducted on how older people’s health and wellbeing in different countries has been impacted by the COVID-19 pandemic. The aim of this study was to develop methodology that would allow us to compare elderly populations, aged 67 + in Latvia and Iceland, and to discuss the potential impact of diverging factors on the association between loneliness, social isolation and health.Methods Quantitative data on 420 respondents from Wave 8 of the Survey of Health, Ageing and Retirement in Europe (SHARE) was utilized in Latvia. Data on health and wellbeing of elderly in Iceland from a HL20 study with 1033 respondents was used to provide comparative analytic material for studying the differences between Latvia and Iceland, and within each country.Results The study revealed considerable differences between the countries regarding the frequency of loneliness and social isolation. About 80% of Latvian respondents felt socially isolated and 45% were lonely, compared to 42.7% socially isolated and 30% lonely Icelanders. In general, more elderly people in Latvia experienced difficulties than their peers in Iceland. Social isolation tends to differ across genders and age groups in both countries. This is related to marital and employment status, financial situation, and education. COVID-19 had a stronger deteriorating effect on mental and physical health among both lonely Latvian and Icelandic respondents. However, health deterioration was stronger amongst more socially isolated Icelanders compared to Latvians.Conclusions The study suggests that social isolation is a contributing factor and increases the risk of loneliness, which might have been enhanced by restrictions during the COVID-19 pandemic.
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