Reproductive Strategies of Erpobdella punctata (Hirudinoidea) in Two Temporary Ponds

Oikos ◽  
1977 ◽  
Vol 29 (2) ◽  
pp. 313 ◽  
Author(s):  
R. W. Davies ◽  
T. B. Reynoldson ◽  
R. P. Everett
2020 ◽  
Vol 638 ◽  
pp. 107-121 ◽  
Author(s):  
BS Rangel ◽  
NE Hussey ◽  
Y Niella ◽  
LA Martinelli ◽  
AD Gomes ◽  
...  

Throughout evolutionary history, elasmobranchs have developed diverse reproductive strategies. Little focused work, however, has addressed how neonatal nutritional state is affected by differing degrees of maternal investment associated with these markedly different reproductive strategies. To investigate the effect of maternal investment on the nutritional quality of pups during the early life history of an extremely viviparous elasmobranch, quantitative biomarker analysis including lipids, fatty acids and stable isotopes was conducted. Using the cownose ray Rhinoptera bonasus (histotrophic viviparous) as a model, we found that pups were initially born in a positive nutritional state, enriched in physiologically important essential fatty acids and nitrogen and carbon stable isotope values (δ15N and δ13C), a result of maternal intrauterine transfer. A systematic decrease in some fatty acids and δ15N values, as well as a decrease in cholesterol with growth, confirmed that these substrates were derived from maternal resources and used in initial metabolic processes following birth. An observed increase in condition factor, plasma essential fatty acids and triglyceride:cholesterol ratio with increasing body size identified a progression towards successful independent foraging with pups not displaying marked nutritional deficiency or fasting phases. Our multi-tracer approach allowed the identification of 2 size classes of young rays (<50 and <70 cm disc width) that displayed distinct physiological states. Since prenatal maternal investment is critical for offspring condition and to promote successful foraging post birth, understanding the trophic ecology and physiological state of pups during their first year is critical to guide management and conservation within nursery grounds.


2013 ◽  
Vol 20 (3) ◽  
pp. 286-299
Author(s):  
Peng Deli ◽  
Zhang Zhiqiang ◽  
Niu Yang ◽  
Yang Yang ◽  
Song Bo ◽  
...  

1981 ◽  
Vol 118 (1) ◽  
pp. 129-134 ◽  
Author(s):  
M. J. McLeod ◽  
D. J. Hornbach ◽  
S. I. Guttman ◽  
C. M. Way ◽  
A. J. Burky

Author(s):  
Agnieszka Napierała ◽  
Jerzy Błoszyk

AbstractThe necessity of monitoring changes occurring in soil compels us to look for new methods that will allow easy and precise evaluation of the soil quality in a given area. One proposed method is the maturity index (MI) – an index that is based on the distribution of species along the r-to-K continuum in examined populations. In this study, mites from the suborder Uropodina (Acari: Mesostigmata) were examined for their appropriateness in MI-based assessments of soil quality. The first aim of the study was to establish the criteria on the basis of which the evaluation of the r-to-K reproductive strategies was conducted for Uropodina in the examined communities. The second aim was to evaluate the performance of the maturity index of communities of Uropodina as indicator of human-caused disturbance in five areas that are legally protected in Poland. The selected areas were: Białowieża Primeval Forest, Gorce National Park, and three nature reserves: Jakubowo, Las Grądowy nad Mogilnicą, and Cisy Staropolskie im. Leona Wyczółkowskiego. We found that as many as 68 out of the 96 analyzed Uropodina species in Poland are K-stategists. The highest values of the maturity index were recorded for the nature reserves Cisy Staropolskie im. Leona Wyczółkowskiego and the Białowieża Primeval Forest.


Wetlands ◽  
2021 ◽  
Vol 41 (6) ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Mauro Fois ◽  
Annalena Cogoni ◽  
Gianluigi Bacchetta

AbstractPlants are key elements of wetlands due to their evolutionary strategies for coping with life in a water-saturated environment, providing the basis for supporting nearly all wetland biota and habitat structure for other taxonomic groups. Sardinia, the second largest island of the Mediterranean Basin, hosts a great variety of wetlands, of which 16 are included in eight Ramsar sites. The 119 hydro- and hygrophilous vascular plant taxa from Sardinia represent the 42.6% and 37.9% of the number estimated for Italy and Europe, respectively. Moreover, around 30% of Sardinia’s bryological flora, which is made up of 498 taxa, is present in temporary ponds. An overview at regional scale considering algae is not available, to our knowledge, even though several specific studies have contributed to their knowledge. In order to find the most investigated research themes and wetland types, identify knowledge gaps and suggest recommendations for further research, we present a first attempt to outline the work that has been hitherto done on plants in lentic habitats in Sardinia. Three plant groups (algae, bryophytes and vascular plants), and five research themes (conservation, ecology, inventory, palaeobotany and taxonomy) were considered. After a literature review, we retained 202 papers published from 1960 to 2019. We found that studies on vascular plants, as plant group, were disproportionately more numerous, and inventories and ecology were the most investigated research themes. Although efforts have recently been made to fill these long-lasting gaps, there is a need for updating the existing information through innovative methods and integrative approaches.


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