Changes in catch rates and length and age at maturity, but not growth, of an estuarine plotosid (Cnidoglanis macrocephalus) after heavy fishing

The hypothesis that heavy fishing pressure has led to changes in the biological characteristics of the estuary cobbler (Cnidoglanis macrocephalus) was tested in a large seasonally open estuary in southwestern Australia, where this species completes its life cycle and is the most valuable commercial fish species. Comparisons were made between seasonal data collected for this plotosid (eeltail catfish) in Wilson Inlet during 2005–08 and those recorded with the same fishery-independent sampling regime during 1987–89. These comparisons show that the proportions of larger and older individuals and the catch rates in the more recent period were far lower, i.e., they constituted reductions of 40% for fish ≥430 mm total length, 62% for fish ≥4 years of age, and 80% for catch rate. In addition, total mortality and fishing-induced mortality estimates increased by factors of ~2 and 2.5, respectively. The indications that the abundance and proportion of older C. macrocephalus declined between the two periods are consistent with the perception of long-term commercial fishermen and their shift toward using a smaller maximum gill net mesh to target this species. The sustained heavy fishing pressure on C. macrocephalus between 1987–89 and 2005–08 was accompanied by a marked reduction in length and age at maturity of this species. The shift in probabilistic maturation reaction norms toward smaller fish in 2005–08 and the lack of a conspicuous change in growth between the two periods indicate that the maturity changes were related to fishery-induced evolution rather than to compensatory responses to reduced fish densities

Effects of fishery protection on biometry and genetic structure of two target sea cucumber species from the Mediterranean Sea

Sea cucumber fisheries are now occurring in most of the tropical areas of the world, having expanded from its origin in the central Indo-Pacific. Due to the overexploitation of these resources and the increasing demand from Asian countries, new target species from Mediterranean Sea and northeastern Atlantic Ocean are being caught. The fishery effects on biometry and genetic structure of two target species (Holothuria polii and H. tubulosa) from Turkey, were assessed. The heaviest and largest individuals of H. polii were found into the non-fishery area of Kusadasi, also showing the highest genetic diversity. Similar pattern was detected in H. tubulosa, but only the weight was significantly higher in the protected area. However, the observed differences on the fishery effects between species, could be explained considering the different percentage of catches (80% for H. polii and 20% for H. tubulosa)

Changes in catch rates and length and age at maturity, but not growth, of an estuarine plotosid (Cnidoglanis macrocephalus) after heavy fishing

The hypothesis that heavy fishing pressure has led to changes in the biological characteristics of the estuary cobbler (Cnidoglanis macrocephalus) was tested in a large seasonally open estuary in southwestern Australia, where this species completes its life cycle and is the mostvaluable commercial fish species. Comparisons were made between seasonal data collected for this plotosid(eeltail catfish) in Wilson Inlet during 2005–08 and those recorded with the same fishery-independent sampling regime during 1987–89. These comparisons show that the proportions of larger and older individuals and the catch rates in themore recent period were far lower, i.e., they constituted reductions of 40% for fish ≥430 mm total length, 62% for fish ≥4 years of age, and 80% for catch rate. In addition, total mortality and fishing-induced mortality estimates increased by factors of ~2 and 2.5, respectively. The indications that the abundance and proportion of older C. macrocephalus declined between the two periods are consistent with the perception of long-term commercial fishermen and their shift toward using a smaller maximum gill net mesh to target this species. The sustained heavy fishing pressure on C. macrocephalus between 1987–89 and 2005–08 was accompanied by a marked reduction in length and age at maturity of this species. The shift in probabilistic maturation reaction norms toward smaller fish in 2005–08and the lack of a conspicuous change in growth between the two periods indicate that the maturity changes were related to fishery-induced evolution rather than to compensatoryresponses to reduced fish densities

T cell signatures associated with reduced Chlamydia trachomatis reinfection in a highly exposed cohort

Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection globally. Understanding natural immunity to CT will inform vaccine design. This study aimed to profile immune cells and associated functional features in CT-infected women and determine immune profiles associated with reduced risk of ascended endometrial CT infection and CT reinfection. PBMCs from CT-exposed women were profiled by mass cytometry, and random forest models identified key features that distinguished outcomes. CT+ participants exhibited higher frequencies of CD4+ Th2, Th17, and Th17 double-negative (Th17 DN) CD4+ T effector memory (TEM) cells than uninfected participants with decreased expression of T cell activation and differentiation markers. Minimal differences were detected between women with or without endometrial CT infection. Participants who remained follow-up negative (FU–) showed higher frequencies of CD4+ T central memory (TCM) Th1, Th17, Th1/17, and Th17 DN but reduced CD4+ TEM Th2 cells than FU+ participants. Expression of markers associated with central memory and Th17 lineage was increased on T cell subsets among FU– participants. These data indicate that peripheral T cells exhibit distinct features associated with resistance to CT reinfection. The highly plastic Th17 lineage appears to contribute to protection. Addressing these immune nuances could promote efficacy of CT vaccines

Reduced Endometrial Ascension and Enhanced Reinfection Associated With Immunoglobulin G Antibodies to Specific <i>Chlamydia trachomatis</i> Proteins in Women at Risk for Chlamydia

Abstract Background Previous research revealed antibodies targeting Chlamydia trachomatis elementary bodies was not associated with reduced endometrial or incident infection in C. trachomatis–exposed women. However, data on the role of C. trachomatis protein–specific antibodies in protection are limited. Methods A whole-proteome C. trachomatis array screening serum pools from C. trachomatis–exposed women identified 121 immunoprevalent proteins. Individual serum samples were probed using a focused array. Immunoglobulin (Ig) G antibody frequencies and endometrial or incident infection relationships were examined using Wilcoxon rank sum test. The impact of the breadth and magnitude of protein-specific IgGs on ascension and incident infection were examined using multivariable stepwise logistic regression. Complementary RNA sequencing quantified C. trachomatis gene transcripts in cervical swab samples from infected women. Results IgG to pGP3 and CT_005 were associated with reduced endometrial infection; anti-CT_443, anti–CT_486, and anti–CT_123 were associated with increased incident infection. Increased breadth of protein recognition did not however predict protection from endometrial or incident infection. Messenger RNAs for immunoprevalent C. trachomatis proteins were highly abundant in the cervix. Conclusions Protein-specific C. trachomatis antibodies are not sufficient to protect against ascending or incident infection. However, cervical C. trachomatis gene transcript abundance positively correlates with C. trachomatis protein immunogenicity. These abundant and broadly recognized antigens are viable vaccine candidates. </jats:sec