And within these communities, siphonophores
rule, consuming so much food that they compete with big, hard-bodied carnivores such as sharks and whales.
Palma & Silva (2006) noted that siphonophore
communities show a distinct separation between the sub-tropical waters of the gyre and the subantarctic waters east of 78[degrees]W (in the Humboldt Current upwelling zone).
While the slugs without shells are able to attack Cnidaria and devour their tentacles--indeed, even those of a Portuguese-man-of-war siphonophore
(Thompson and Bennett, 1969)--they also elegantly creep, move, bend, and swim with a flexible skin, waving their rhinophores and cerata on contact with their prey's tentacles.
It is speculated that such a condition may have favored the siphonophore
outbreak observed along the Pacific coast of Costa Rica.
In the two siphonophore
species examined, Porpita and Physalia, the tentacles bear large assemblies of cnidocytes, called cnidosacs, that appear as a line of hemispheres or spheres arranged along one edge of each tentacle.
This point circulates in the x-y plane in one direction (clockwise for the ascidian spermatozoa observed in the vicinity of the glass slide surface, and counterclockwise for the siphonophore
spermatozoa), with a radius of curvature that changes depending on the attractant concentration and on time.
Seasonal abundance of the siphonophore
, Nanomia bijuga, in Monterey Bay.
Influence of siphonophore
behavior on their natural diets; evidence for aggressive mimicry.
The most transparent tissues (at 480 nm) were hydromedusa mesoglea (66%), followed by Cystosoma (42%), ctenophore mesoglea (41%), siphonophore
mesoglea (39%), pelagic tunicares (excluding Pyrosoma) (33%), Sagitta (24%), and the translucent portions of the hydromedusae and ctenophores (24%).
By October, ten taxonomic groups contributed 95% of the zooplankton community: copepods, chaetognaths, euphausiids, fish larvae, amphipods, siphonophores
, cladocerans, polychaetes, medusas and ostracods (Fig.
There is a new moon on Saturday which will give us spring tides which means we will have larger exposed areas of coastline where we are likely to see these most venomous siphonophores
, or to most of us, jellyfish.
In response, this article defends a plural ontology of process, activity, event, and continuant, and shows how a sortalist philosophy of substance that makes Hilary Putnam's distinction of realism from metaphysical realism can treat disputed questions concerning the identity and individuation of colonial siphonophores
, slime molds, and plant-colonies.