Diel and seasonal timing of sound production by black drum (Pogonias cromis)

Acoustic recorders were used to document black drum (Pogonias cromis) sound production during their spawning season in southwest Florida. Diel patterns of sound production were similar to those of other sciaenid fishes and demonstrated increased sound levels from the late afternoon to early evening—a period that lasted up to 12 hours during peak season. Peak sound production occurred from January through March when water temperatures were between 18° and 22°C. Seasonal trends in sound production matched patterns of black drum reproductive readiness and spawning reported previously for populations in the Gulf of Mexico. Total acoustic energy of nightly chorus events was estimated by integration of the sound pressure amplitude with duration above a threshold based on daytime background levels. Maximum chorus sound level was highly correlated with total acoustic energy and was used to quantitatively represent nightly black drum sound production. This study gives evidence that long-term passive acoustic recordings can provide information on the timing and location of black drum reproductive behavior that is similar to that provided by traditional, more costly methods. The methods and results have broad application for the study of many other fish species, including commercially and recreationally valuable reef fishes that produce sound in association with reproductive beha

Dietary Habits of the Gafftopsail Catfish, Bagre marinus, in Tarpon Bay and Pine Island South, Florida

A total of 507 gafftopsail catfish, Bagre marinus, were captured by hook and line in Tarpon Bay and neighboring Pine Island Sound, Florida from June 3, 1999 to May 6, 2000 in order to identify foods of this understudied species. A total of 86 (17.0%) specimens contained only unidentifiable food, and 187 (36.9%) specimens were found with empty stomachs. Based on the index of relative importance, the pink shrimp, Farfantepenaeus duorarum, was the most important food for specimens ≤200 mm fork length (FL), amphipods the most important food for specimens 201-300 mm FL, and unidentifiable fish the most important food for specimens ≥301 mm FL. Diet of B. marinus was also compared among four seasons: June through August; September through November, December through February, and March through May. Unidentifiable fish was the most important food for June through August and September through November. Clupeid fishes were the most important food for December through February. The amphipod Ampelisca abdita was the most important food for March through May. The wide variety of foods consumed by B. marinus indicates an opportunistic feeding strategy

A Comparison of Macroepifauna Among Vegetated and Unvegetated Habitats in a South Florida Estuary Using a Passive Sampling Gear

We compared abundance, richness, diversity, and community structure of macroepifauna among the seagrasses Halodule wrightii, Thalassia testudinum, and Syringodium filiforme, and unvegetated substrate in Tarpon Bay, Caloosahatchee River estuary, Florida. Sampling was conducted using wire-mesh minnow traps deployed over fifty-six 24-h periods from Jan. 1999 to Jan. 2000. A total of 36, 35, 28, and 28 species were identified from Halodule, Thalassia, Syringodium, and unvegetated samples, respectively. The gastropod Nassarius vibex was the most abundant species from Halodule and unvegetated substrate, whereas the pinfish (Lagodon rhomboides) was the most abundant species from Thalassia and Syringodium. Abundance of these codominant species varied seasonally throughout the study. For all taxa combined and for codominants, each seagrass contained greater averages than unvegetated substrate in each season. Seagrasses typically had higher average species richness and diversity than unvegetated substrate in each season. Results indicate that Tarpon Bay typifies subtropical estuaries in that its epifaunal community is dominated by few species, faunal abundances vary seasonally, and more organisms are found in seagrasses than in unvegetated areas. Our results serve as a foundation to compare against future research in an understudied system

Effects of Hurricane Charley on fish chorusing

Hurricane Charley, a category 4 hurricane, passed through Charlotte Harbor, Florida, directly over an autonomous underwater acoustic datalogger used to record sound production by fishes associated with courtship and spawning. Acoustic recordings made on 9 days prior to the storm, during and 3 days after the storm provided unprecedented documentation of the hurricane's passage and its effect on fishes' calling behaviour. The hurricane did not inhibit nightly chorusing events of spawning fish. Sound levels produced by spawning fish on the night of and 3 days after the hurricane were higher and lasted longer than any of the 9 days recorded prior to the hurricane

Unveiling bifidobacterial biogeography across the mammalian branch of the tree of life

Internally transcribed spacer (ITS) rRNA profiling is a novel tool for detailed analysis of microbial populations at low taxonomic ranks. Here we exploited this approach to explore species-level biogeography of the Bifidobacterium genus across 291 adult mammals. These include humans and 13 other primates, domesticated animals, such as dogs, cats, cows, sheep, goats, horses and pigs, and 46 additional species. The collected profiles revealed the presence of 89 putative novel bifidobacterial taxa in addition to 45 previously described species. Remarkably, in contrast to what is currently known for many gut commensals, we did not observe host-specialization among bifidobacterial species but rather their widespread distribution across mammals. Moreover, ITS rRNA profiling of wild relatives of domesticated dogs, rabbits and pigs clearly indicates that domestication and close contact with humans have impacted on the composition of the fecal bifidobacterial population. These data were complemented by analysis of bifidobacterial communities in milk of eight mammalian families, showing that bifidobacteria represent prototypical early gut microbiota members which are inherited by newborns from their lactating mother. Thus this study highlights the role of bifidobacteria as pioneering gut colonizers of a wide range of mammals

The genome of the sea urchin Strongylocentrotus purpuratus.

International audienceWe report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes