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Characterisation of the Echinogammarus marinus (Leach) (Amphipoda) population in the Mondego estuary
| Content Provider | Semantic Scholar |
|---|---|
| Author | Marques, João Carlos Maranhão, Paulo Abrão C. Pardal, Miguel Ângelo |
| Copyright Year | 2014 |
| Abstract | A benthic sampling program was carried out in 1985/86, in winter and summer periods, to characterise the intertidal community structure in the Mondego estuary (Portugal). Echinogammarus marinus (Amphipoda, Gammaridae) was considered a key species in rocky substrates, particularly in association with Fucus spp, and consequently a study on its life cycle and population dynamics was carried out. E. marinus showed an aggregated spatial distribution, and the population density changed seasonally. with peaks during spring and summer. No migratory pattems were detected between the estuary and the sea, but migrations inside the estuary might occur. An analysis of the popuriüion structure and dynamics was carried out based on the assumption that, although sexual activity was continuous through out the year; it would be possible to recognise and track population groups from their origin up to their total disappearance. Growth was continuous through life, although growth rates were higher during the early phases, and females were morphologically recognisable at smaller sizes than males. ln addition, males became larger than females. Females reached sexual maturity before males, producing a succession of broods during the rest of their life. Fecundity increased with the size of females. Life span was estimated to be lOto 12 months, but females showed higher mortality rates than males. This was probably due to higher costs of reproduction, which might cause a decrease in female survival. Sexual activity showed an increase in spring and summer. ln the Mondego estuary, E. marinus is a semi-annual species, with three or four generations per year. Reproduction through the year; iteroparous females, high fecundity, and a multivoltine life cycle clearly suggest an r adaptive strategy. Production of E. marinus in the algal cover of Fucus spp. was estimated. Growth production (P) ranged from 6.36 to 8.81 gm2.y1 (AFDW) (76.16 to I 05.48KJ.m-2.y ') and elimination e.,roduction (E) from 6.33 to I 1.44 ~.m,2.y1 (AFDW) (75.84 to 137.04 KJ.m,2.yr l). PIB ratios ranged from 6, I to 6,3 and ElB ratios from 6,28 to 7,89. The present contribution was mostly based on a previously published paper (Marques and Nogueira 1991). <,> IMAR Instituto do Mar; Centro Interdisciplinar de Coimbra, ale Departamento de Zoologia, Universidade de Coimbra 3004 5 17 Coimbra, Portugal 399 |
| File Format | PDF HTM / HTML |
| DOI | 10.14195/978-989-26-0336-0_27 |
| Alternate Webpage(s) | https://digitalis-dsp.uc.pt/bitstream/10316.2/32715/1/27-%20Aquatic%20Ecology%20of%20the%20Mondego%20River.pdf.pdf |
| Alternate Webpage(s) | https://doi.org/10.14195/978-989-26-0336-0_27 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
