Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

Eustrongylides spp. are cosmopolitan parasitic nematodes with several freshwater fish species as intermediate or paratenic hosts, rarely reported zoonotic agents. This work aims to report, for the first time, occurrence of this parasite in specimens big-scale sand smelt (Atherina boyeri) caught lake Massaciuccoli (Northwest Tuscany, Italy). Totally 3317 A. boyeri were collected three different ...

Complex life cycles have evolved independently numerous times in marine animals as well as in disparate algae. Such life histories typically involve a dispersive immature stage followed by settlement and metamorphosis to an adult stage on the sea floor. One commonality among animals exhibiting transitions of this type is that their larvae pass through a 'precompetent' period in which they do no...

The introduction of non-native fish species is known to have adverse effects on aquatic ecosystems, but their effect plateau lakes not well studied. In this study, we examined the Japanese smelt (Hypomesus nipponensis) invasion assemblage in Lake Erhai, a subtropical lake southwestern China. Through cluster analysis and non-metric multidimensional scaling (NMDS), found significant shift: popula...

An Investigation of Factors Affecting the Decline of Delta Smelt (Hypomesus transpacificus) in the Sacramento-San Joaquin Estuary William J. Miller a , Bryan F. J. Manly b , Dennis D. Murphy c , David Fullerton d & Rob Roy Ramey e a San Luis & Delta-Mendota Water Authority, Point Richmond, California, USA b Western Ecosystem Technology, Inc., Cheyenne, Wyoming, USA c Biology Department, Univers...

Dr X is back from her annual leave. Dr Y, the locum doctor, reports on the patients he saw during her absence, including a 40 year old teacher who had sprained her right ankle. Returning from a conference, she had stumbled while walking down the stairs with a heavy bag. Examination revealed a moderately swollen lateral right ankle. The patient was able to walk but was clearly in pain. Her breat...