A Standardized Terminology for Describing Reproductive Development in Fishes

As the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This hasmade it difficult for both scientists and resourcemanagers to communicate and for comparisons to be made among studies. We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and female elasmobranch and teleost fishes. These phases were chosen because they define key milestones in the reproductive cycle; the phases include immature, developing, spawning capable, regressing, and regenerating. Although the temporal sequence of events during gamete development in each phase may vary among species, each phase has specific histological and physiological markers and is conceptually universal. The immature phase can occur only once. The developing phase signals entry into the gonadotropin-dependent stage of oogenesis and spermatogenesis and ultimately results in gonadal growth. The spawning capable phase includes (1) those fish with gamete development that is sufficiently advanced to allow for spawning within the current reproductive cycle and (2) batch-spawning females that show signs of previous spawns (i.e., postovulatory follicle complex) and that are also capable of additional spawns during the current cycle. Within the spawning capable phase, an actively spawning subphase is defined that corresponds to hydration and ovulation in females and spermiation in males. The regressing phase indicates completion of the reproductive cycle and, for many fish, completion of the spawning season. Fish in the regenerating phase are sexually mature but reproductively inactive. Species-specific histological criteria or classes can be incorporated within each of the universal phases, allowing for more specific divisions (subphases) while preserving the overall reproductive terminology for comparative purposes. This terminology can easily be modified for fishes with alternate reproductive strategies, such as hermaphrodites (addition of a transition phase) and livebearers (addition of a gestation phase)

Reddened, Redshifted, or Intrinsically Red? Understanding Near-Ultraviolet Colors of Type Ia Supernovae

Understanding the intrinsic colors of Type Ia supernovae (SNe Ia) is important to their use as cosmological standard candles. Understanding the effects of reddening and redshift on the observed colors are complicated and dependent on the intrinsic spectrum, the filter curves, and the wavelength dependence of reddening. We present ultraviolet and optical data of a growing sample of SNe Ia observed with the Ultra-Violet/Optical Telescope on the Swift spacecraft and use this sample to re-examine the near-UV (NUV) colors of SNe Ia. We find that a small amount of reddening (E(B-V)=0.2 mag) could account for the difference between groups designated as NUV-blue and NUV-red, and a moderate amount of reddening (E(B-V)=0.5 mag) could account for the whole NUV-optical differences. The reddening scenario, however, is inconsistent with the mid-UV colors and color evolution. The effect of redshift alone only accounts for part of the variation. Using a spectral template of SN2011fe we can forward model the effects of redshift and reddening and directly compare with the observed colors. We find that some SNe are consistent with reddened versions of SN2011fe, but most SNe Ia are much redder in the uvw1-v color than SN2011fe reddened to the same b-v color. The absolute magnitudes show that two of five NUV-blue SNe Ia are blue because their near-UV luminosity is high, and the other three are optically fainter. We also show that SN2011fe is not a "normal" SN Ia in the UV, but has colors placing it at the blue extreme of our sample

Emerging Issues and Methodological Advances in Fisheries Reproductive Biology

Although incorporating detailed reproductive data into all stock assessments is not a practical goal, the need to understand how reproductive biology affects population productivity is being increasingly recognized. More research focused on reproductive biology-coupled with a shift towards a resilience perspective in fisheries science-is resulting in challenges to many long-held assumptions; the emergence of important new issues; and identification of the need to improve data and methods used in reproductive studies. Typically, data for reproductive studies are based on an assessment of gonadal development, which is most accurately evaluated with histology. This special section of Marine and Coastal Fisheries contains contributions from a workshop on the gonadal histology of fishes that was held in Cadiz, Spain, during June 2009. These papers cover a wide range of species and reproductive topics while introducing improved and new histological techniques. In this introduction, we address the following needs: (1) to employ standardization, thereby improving our ability to conduct comparative studies; (2) to better understand patterns of gonadal development and spawning events over time; and (3) to move beyond the spawning stock biomass paradigm. We identify the contributions of special section papers to these topics and conclude by suggesting needs for future research and integration of reproductive data into both conceptual and quantitative models to better understand how reproductive performance affects population dynamics

Notes on the Biology of Invasive Lionfish (Pterois sp.) from the Northcentral Gulf of Mexico

The first confirmed sightings of lionfish in the Gulf of Mexico occurred in 2010 (Schofield 2010), where they were reported in the southern GOM off the Yucatan Peninsula, Mexico (Aguilar-Perera and Tuz-Sulub 2010); in 2012 more than 1,500 lionfish were collected from northern GOM locations ranging from Florida to Texas (Fogg et al. 2013). However, other than visual observations (mostly from recreational divers), there is relatively little information on the biology and ecology of lionfish in the northern GOM. The life history of invasive species can vary as they colonize new habitats and areas (Bøhn et al. 2004); thus, biological parameters described for lionfish along the US southeast coast, the Bahamas, and the Caribbean may differ as the species invades the GOM. Recently, Fogg et al. (2013) provided information on length-weight and sex ratios of northern GOM lionfish. Here, we report biological data from 4 lionfish captured during fishery-independent sampling in nearshore GOM waters off Alabama in May 2012

AN ASSESSMENT OF THE PROPOSED NEW RISK MANAGEMENT PROGRAMS

The purpose of this assessment as outlined in the terms of reference is: "To obtain an assessment by an independent third party of the expected performance of the proposed new business risk management program's proposed New NISA and production insurance relative to the current set of risk management programming, including NISA, CFIP, crop insurance and companion programs." Within this context, the specific mandate and scope is to assess "the extent to which the current and proposed programs meet the objectives set out by Agriculture Ministers for business risk management programming, as follows: · to ensure programs are responsive to demand and that government dollars are directed to areas of need with respect to income stabilization, disaster mitigation, insurance coverage and investment; · to provide equal treatment for farmers across Canada facing similar risk situations; · to minimize the distortion of farmers' production and marketing decisions; · to focus on management of risks related to the stability of the entire farm and to avoid duplication of payments; · to be relatively simple and easy to understand; and · to facilitate long term planning by farmers."Risk and Uncertainty,

The Reproductive Biology of Small Fishes and the Clutch Concept: Combining Macroscopic and Histological Approaches

Accurate estimates of reproductive parameters important in understanding life history evolution and conservation of small fishes are dependent upon careful assignment of ovarian phases. Proper assignment is based upon the stages of propagule (oocyte) development, oocyte maturation and the location of any clutch or portion thereof within the ovaries. Macroscopic inspection and assignment of ovarian developmental phases have often been used for small freshwater fishes. By contrast, histological methods for assignment of reproductive phases have been developed and are widely used for marine fishes, but they have rarely been used for small freshwater fishes. We review oocyte development, ovum maturation, and the ovarian cycling process using both macroscopic and histological approaches which incorporate the clutch concept. New terminology, including three actively spawning phases based on macroscopic appearance of the clutch (actively spawning-maturation, actively spawning-hydration, actively spawning-ovulation), is proposed. We assert that combining histological and macroscopic methodologies, shown to be complementary, will allow a more accurate and precise understanding of the reproductive biology of small fishes—especially freshwater fishes experiencing effects of habitat change and loss of habitat