The early llfe of cod was studied dunng a survey programme covenng the northeastern North Sea, the Skagerrak and the Kattegat In May 1992 Our aim was to asses the interrelated effects of physical and biolog~cal factors on d~stnbutlon, growth and surv~val of larval cod In the present paper we descnbe the ~d e n t~f i e d nursery areas of larvae/juveniles and analyse the connect~on between the distribution of cod and hydrograph~cal (frontal) charactenstics of the areas A total area of 67000 km2 was covered by statlons in a 10 X 10 nautlcal mile grid Sahn~ty, temperature, N 0 3 + N 0 2 and chlorophyll concentrat~on were proflled through the water column Zooplankton were sampled by a submers~ble pump and abundance of fish larvae/juveniles were estlrnated by depth-integrating tows of a 2 m nng net The hydrographlcal measurements indicated a shelf break front posit~oned along the shelf slope In the southern part of the lnvestigatlon area, and w i t h~n the zone of the front we observed enhanced prunary product~on and abundance of both phyto-and zooplankton The distnbut~on of larval and juvenlle cod was also related to the hydrography, the abundance of cod peaked wlthln a restricted zone and the aggregat~ons extended as a cont~nuous band along the front We suggest that the observed concurrence between a hydrograph~c front and cod larvae/juvenlles is a general and recurrent phenomenon based on the spawning h a b~t s of cod and aggregation due to flow convergence at the front

The brown widow spider, Latrodectus geometricus C. L. Koch, has become newly established in southern California during the first decade of the 21st century. Brown widows and egg sacs were collected within the urban Los Angeles Basin using timed searches. We also collected and compared the abundance and distribution of the native western black widow spider, Latrodectus hesperus Chamberlin & Ivie, to brown widows. Brown widows were very common around urban structures especially outside homes, in parks, under playground equipment, in plant nurseries and landscaping areas, greatly outnumbering native western black widows, and were very rare or nonexistent in garages, agricultural crops, and natural areas. Western black widows predominated in xeric habitats and were less prevalent around homes. Neither species was found in the living space of homes. In southern California, envenomation risk exists because brown widows are now common in urban areas and the spiders hide where people place their fingers and exert pressure to move objects (e.g., under the curled lip of potted plants, in the recessed handle of plastic trash bins). Nonetheless, brown widow spider bites are less toxic than those of native western black widow spiders and, hence, if they are displacing black widows, overall widow envenomation risk may actually be lower than before brown widow establishment.

No abstract

The brown widow spider, Latrodectus geometricus C. L. Koch, 1841, is a non-native arachnid that became established in peninsular Florida in the 1930s (Pearson 1936). In the first decade of the 21 st century, it rapidly spread through the southeastern UnitedStates and southern California (Brown et al. 2008;Vincent et al. 2008;Vetter et al. 2012a) and has become a ubiquitous urban pest species in the Los Angeles Basin and San Diego area (Vetter et al. 2012b). One possible reason for its success lies in its fecundity, as it can produce an egg sac every four days during its earliest ovipositions and averages 22 egg sacs in a lifetime (Bouillon and Lekie 1961).