Evaluation of larval quality of viviparous scorpionfish Sebastiscus marmoratus

The aim of this study was to develop an acute test for larval quality in the viviparous scorpionfish Sebastiscus marmoratus. Rearing experiments until day 13 post parturition were conducted to investigate the survival of larvae for 13 different batches, and tolerance to starvation of larvae was examined and expressed by the survival activity index (SAI). The morphological characters, enzyme activity, and swimming behavior of larvae on day 0 and 1 were also observed, followed by the correlation analysis between SAI. Larvae with high SAI (≥26) showed significantly higher survival on day 13 than larvae with low SAI, which confirmed that SAI is a reliable index that can be used to evaluate larval quality, similar to the former findings. The esterase activity (r=−0.713, P<0.01), swim frequency (r=−0.735, P<0.01) and swimming speed (r=−0.588, P<0.05) of larvae on day 0 were significantly and negatively correlated with SAI. It was concluded that enzyme activity and behavioral characters of larvae just after parturition can be a real-time index for evaluating the larval quality of this species.     

Details of the digestive system in the midgut of Coptotermes formosanus Shiraki

Wood-feeding termites have evolved an efficient cellulose-decomposing system. The termite has two independent cellulose-digesting systems: one in the midgut and the other in the hindgut. Because the digestion system in the midgut should be the sole source of soluble sugars for the host termite, the details of the decomposition of wood particles in the midgut were clarified in one of the most common pest species, Coptotermes formosanus. The spatial distribution of cellulase in the midgut was found by immunohistochemistry, and the amount of endogenous cellulases and the volume of the endoperitrophic space were determined. The size of wood particles in the foregut and the midgut were compared. The results showed that one of the characteristics of wood degradation by termites is the mechanical grinding of food by the mandibles and the cuticular apparatus of the foregut. This process greatly increases the surface area of the substrates. Extremely high concentrations of cellulase attack the ground-up wood in the midgut, and the glucose produced is removed quickly through the peritrophic membrane.     

Effect of estrus synchronization treatment after luteolysis on Holstein heifers as embryo transfer recipients

This study was designed to evaluate the effect of estrus synchronization treatments on recipient heifers for embryo transfer (ET). Holstein heifers were separated into the following three groups: (i) an administration of 50 µg GnRH (gonadotropin‐releasing hormone) analog was given to heifers at a random stage of the estrus cycle, followed 7 days later by two administrations of 7.5 mg prostaglandin F2 alfa analog (PG) as control; (ii) another administration of 100 µg GnRH was given to the control group at 48 h after the administration of PG as the second GnRH group; and (iii) an administration of 0.75 mg estradiol benzoate (E2) was given to the control group at 24 h after the administration of PG as the E2 group. Each method caused estrus synchronization. Fresh embryos were nonsurgically transferred into the suitable recipients that had a functional corpora lutea (CL) 7 days after estrus. The E2 group showed a significantly higher (P < 0.01) rate of estrus synchronization (98.9%) at 1–3 days after PG administration and the final pregnancy rate of the E2 group (50.6%) was also significantly higher than the other groups (37.1%, P < 0.05 and 30.9%, P < 0.01, respectively). These findings demonstrate that E2 administration 24 h after PG protocol is effective for estrus synchronization of Holstein heifers, thus improving the productivity of ET.     

Recycled ionic liquid 1-ethyl-3-methylimidazolium acetate pretreatment for enhancing enzymatic saccharification of softwood without cellulose regeneration

In this work, pretreatment of wood meals using a recycled ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate ([Emim]Ac), enhanced glucose liberation by enzymatic saccharification, without dissolution of cellulose and lignin. In contrast, previous studies on IL pretreatment have mostly focused on lignocellulosic dissolution to regenerate cellulose and removing lignin. Softwood (Cryptomeria japonica) was pretreated with [Emim]Ac at 60–100 °C for 2–8 h without collecting regenerated cellulose. The pretreatment did not have a strong effect on wood component dissolution (weight of residues: 91.7–98.8%). The residues contained relatively high amounts of lignin (26.6–32.6%) with low adsorption of [Emim]Ac (0.9–2.7%). Meanwhile, the crystallinity index (C _r I) of cellulose in the wood was significantly reduced by pretreatment, from 50.9% to 28.4–37.1%. In spite of the high lignin contents in the residues, their glucose liberation values by enzymatic saccharification using a cellulase mixture were 3–16 times greater than that of untreated wood. A good correlation was found between the saccharification effectiveness of pretreated samples and the C _r I. Although lignin dissolved in [Emim]Ac continued to accumulate after repeated use of [Emim]Ac, the pretreatment was found to be effective for three consecutive cycles without the need to remove the dissolved materials.