Reproductive bionomics of some shallow-water lysianassoids in the Saint Lawrence Estuary, with a review on the fecundity of the Lysianassoidea (Crustacea, Amphipoda)

1990 ◽  
Vol 68 (8) ◽  
pp. 1639-1644 ◽  
Author(s):  
Bernard Sainte-Marie ◽  
Gabriel Lamarche ◽  
Jean-Marc Gagnon

The life history and fecundity of five shallow-water lysianassoids from the Saint Lawrence Estuary were examined. Orchomenella minuta and Or. pinguis are annual and iteroparous (two broods), Psammonyx terranovae is iteroparous (two broods) and probably biennial, and Anonyx sarsi and Onisimus litoralis are biennial and semelparous. Females of A. sarsi and On. litoralis cease feeding on bait shortly before or after oviposition, whereas females of the iteroparous Or. pinguis stop feeding on bait only when broods are in the latest stages of embryo development. These ontogenetic changes may result from gut constriction caused by developing ovaries and broods, or may be due to behavioural changes. Data on the fecundity of the Lysianassoidea are reviewed, and it is concluded that deep-living species are probably much less fecund than shallow-living species. Anonyx nugax, Or. pinguis, and A. sarsi are more fecund than other lysianassoids, possibly because of their high-risk carrion-feeding and suprabenthic foraging activities.

2018 ◽  
Vol 93 (3) ◽  
pp. 416-436 ◽  
Author(s):  
Paola Flórez ◽  
Paula Zapata-Ramírez ◽  
James S. Klaus

AbstractIn this contribution we describe and illustrate 14 coral morphospecies collected from the early Miocene Siamaná (Aquitanian–Burdigalian) and Jimol (late Burdigalian) formations of the Cocinetas Basin in La Guajira Peninsula, northern Colombia. Eleven were identified as already established species including seven genera belonging to the families Mussidae, Pocilloporidae, Poritidae, Siderastreidae, and Milleporidae; the other three remain in open nomenclature. Nine of the 11 species identified (81%) are extinct. The remaining two living species,Siderastrea sidereaandMillepora alcicornis, are common on modern Caribbean reefs. Their presence in the Siamaná Formation extends their temporal range in the Caribbean region to the early Miocene. Most of the taxa described here were hermatypic and zooxanthellate corals of the order Scleractinia, with the exception of the fire coralMillepora alcicornis, of the order Anthothecata, family Milleporidae. The coral fauna recorded in the Siamaná and Jimol formations is typical of shallow and calm waters of the Oligocene–Miocene transition.


1975 ◽  
Vol 53 (7) ◽  
pp. 942-952 ◽  
Author(s):  
T. Amaratunga ◽  
S. Corey

A 17-month field study showed that Mysis stenolepis in Passamaquoddy Bay, New Brunswick lives for about 1 year. Young are released in shallow water early in spring and grow rapidly during the summer. In the fall, young adults migrate to deeper water where they reach sexual maturity. Transfer of sperm lakes place during winter in deeper regions of the Bay. soon after which the males die. Females survive and in spring migrate to shallow waters to release young after which they die. Females breed once and carry an average of 157 young per brood. Developmental stages of the postmarsupial young are described and discussed.


2013 ◽  
Vol 23 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Jerry M. Baskin ◽  
Juan J. Lu ◽  
Carol C. Baskin ◽  
Dun Y. Tan

AbstractMany studies have compared diaspore dispersal ability and degree of dormancy in the two diaspores of dimorphic plant species. A primary goal of these studies was to determine if germination and dispersal characteristics of the two morphs fit within a high risk–low risk (bet-hedging) life-history strategy, i.e. high dispersal/low dormancy in one morph versus low dispersal/high dormancy in the other one. In a survey of 26 papers on 28 diaspore dimorphic species, we found that in 12 of the studies, which were published between 1978 and 2008, seeds were stored, and thus possibly afterripened, before they were tested for germination. The 14 papers that tested fresh seeds were published between 1963 and 2010. Failure to test fresh seeds likely resulted in misinterpretation of the diaspore dispersal/dormancy strategy in some of the species investigated. We conclude that it is imperative that fresh seeds be tested for germination in order to be certain that the correct relationship between dispersal and dormancy is elucidated, and thus that the correct interpretation is made concerning life-history strategy and bet-hedging, in dimorphic species.


2012 ◽  
Vol 90 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Bradley R. Johnston ◽  
Markus Molis ◽  
Ricardo A. Scrosati

Nonconsumptive predator effects on prey behaviour are common in nature, but the possible influence of prey life-history stage on such responses is poorly known. We investigated whether prey life-history stage may be a factor affecting prey feeding activity responses to predator chemical cues, for which we used dogwhelks ( Nucella lapillus (L., 1758)) and their main prey, barnacles ( Semibalanus balanoides (L., 1758)), as a model system. Barnacles use their modified legs (cirri) to filter food from the water column. Through a manipulative laboratory experiment, we tested the hypothesis that the presence of dogwhelks affects the frequency of leg swipes differently in juvenile and adult barnacles. Juveniles showed a similar feeding activity with and without nearby dogwhelks, but adults exhibited a significantly lower frequency of leg swipes when dogwhelks were present. Such an ontogenetic change in the response of barnacles to predatory cues might have evolved as a result of dogwhelks preferring adult barnacles over juvenile barnacles, as found previously. Alternatively, barnacles could learn to recognize predator cues as they age, as shown for other prey species. Overall, our study indicates that the nonconsumptive effects of predators on prey need to be fully understood under consideration of the possible ontogenetic changes in prey responses to predator cues.


1976 ◽  
Vol 54 (5) ◽  
pp. 615-619 ◽  
Author(s):  
Susan Corey

Diastylis sculpta was collected from shallow water (1–15 m) in Passamaquoddy Bay over a 26-month period. D. sculpta produces a rapidly growing and developing summer generation between two successive winter generations. The overwintering generation releases young in mid-July and late August. The summer generation releases young in November. The mean fecundity of the summer-gravid females (78.4) is much greater than the mean fecundity (20.0) of the fall-gravid females. The maximum life-span is 5 months and 12 months for members of the summer and winter generations respectively.


2016 ◽  
Vol 42 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Louise Chavarie ◽  
Kimberly Howland ◽  
Paul Venturelli ◽  
Benjamin C. Kissinger ◽  
Ross Tallman ◽  
...  

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