Abstract. The aim of this study was to determine the effects of maternal traits on reproductive expenditure and energy delivery to the offspring in a capital breeder, the northern elephant seal (Mirounga angustirostris). Changes in maternal and offspring energy reserves and milk-energy delivery were examined in relation to maternal parturition mass, body composition, and age in females and pups breeding at Añ o Nuevo State Reserve, California. Maternal body mass and composition had significant effects on maternal energy expenditure over lactation. Path analysis suggested no significant effects of maternal age on reproductive effort of parous females. The efficiency of milk production increased significantly with maternal age. Offspring metabolism was a relatively small component of maternal energy expenditure, with pups storing 84% of the energy obtained from milk. These effects are an important consequence of the phocid strategy for enabling terrestrial parturition despite marine feeding. This strategy has resulted in an abbreviated and highly efficient lactation system that is strongly impacted by body reserves, linking foraging success at sea with reproductive success on land. Maternal size, body composition, and age were important features of reproduction in northern elephant seals. These characteristics are rarely considered concurrently in life history studies.

Aquatic organisms have various pigments contained in their body and may be an important characteristic for the consumer choice. Carotenoids are the main group of pigments present in aquatic organisms and play an important role not only in colouring but also in the growth, reproduction and maintenance of these animals. As aquatic animals do not have the ability to synthesize carotenoids, they must be ingested in the food, and in some cases, they are converted into forms that are possible to store or use in the animal metabolism. In this work, information was collected about the colour characteristics of aquatic organisms and their influence on aquaculture. Various dietary ingredients, such as vegetables and microorganisms, may be potential sources of pigments for aquaculture species, reducing production costs and dependence on synthetic sources of carotenoids. Some species with aquaculture potential may be better studied in terms of the ability to use carotenoid pigments and their function in the body.

The dive behaviour of 18 female New Zealand fur seals (Arctocephalus forsteri) from Taumaka, Open Bay Islands, New Zealand (43°52'S, 168°53'E), was recorded during early (summer; December-February), mid (autumn; March-May), and late (winter; June-August) lactation. Mean dive depth, dive duration, and bottom time for dives >=6 m in depth increased from summer through winter. Variation in individual seal dive behaviour within a season accounted for approximately 11, 9, and 11% of the observed difference between seasons in dive depth, dive duration, and bottom time, respectively. Seasonal dive data (mean ± 1 SD) were as follows: summer: dive depth 30 ± 37 m, dive duration 1.4 ± 1.1 min, and bottom time 0.5 ± 0.6 min; autumn: dive depth 54 ± 47 m, dive duration 2.4 ± 1.3 min, and bottom time 1.0 ± 0.8 min; winter: dive depth 74 ± 64 m, dive duration 2.9 ± 1.5 min, and bottom time 1.2 ± 1.1 min. Maximum recorded dive depth was 274 m for a 5.67-min dive in autumn. Maximum duration was 11.17 min for a dive to 237+ m in winter. New Zealand fur seals are the deepest diving fur seal species reported thus far. The estimated theoretical aerobic dive limit was exceeded on 18.4% of dives (range of individual values 0.2-57.8%). Females (n = 12) were ashore about 1.8 days at a time during February through November, and this increased to about 4.3 days during December and January. Average time spent away from the rookery ranged from 3 to 15 days.

This work describes the synthesis of spiro 1,3,4‐thiadiazolines from isatin‐β‐thiosemicarbazone acetylation, using microwave irradiation as a source of heating the reaction medium. N‐substituted isatin derivatives were used as substrates to obtain thiosemicarbazones by adding thiosemicarbazide to the isatin ketone carbonyl. The final synthetic step was the reaction of thiosemicarbazones with acetic anhydride under microwave irradiation to get the spiro compounds. Reaction times ranged from 6 to 18 minutes resulting in yields of up to 90%. Biological assays have shown promising antibacterial and antifungal activity, especially spiro thiadiazolines derived from allylated isatins. All the proposed molecules proved to be potential drug candidates based on the results of the in silico investigation, with satisfactory drug‐likeness and drug‐score, respecting Lipinski's rule. The use of the microwave reactor was efficient for the synthesis of thiosemicarbazones and spiro compounds, resulting in a significant reduction in reaction times with conventional heating. Taking into account the threat of antimicrobial resistance, this work presents a series of bioactive molecules that are easily obtained via microwave reaction.

This study aimed to analyse the effects of different water temperatures on the growth, survival and blood physiological parameters of Lophiosilurus alexandri. Juveniles measuring 12.6 AE 0.5 cm and weighing 30.6 AE 3.6 g were subjected to four water temperature regimes: 23, 26, 29 and 32°C with four replicates. The animals were fed twice daily with formulated diet. The experiment lasted for 35 days. Survival was 100% at all water temperatures, and the best temperature for growth was estimated to be 27.8°C using a quadratic regression model. The estimated temperatures for the best feed conversion and highest feed consumption rates were 26.2 and 28.8°C respectively. The fat visceral-somatic index was highest at 32°C. The highest haemoglobin and haematocrit values were 29.4 and 32.1°C respectively. For plasma protein and cholesterol, the lowest values estimated were 23.9 and 24.1°C respectively. Glucose and liver nitrogen content increased with rising temperature. Higher values of total ammonia in the water were observed at higher temperatures. No effects of temperature were seen on the amounts of muscle dry matter, nitrogen, energy content and triglycerides or on the hepatosomatic index. Water temperature has an important role in the developmental and blood physiological parameters of juvenile L. alexandri, and the quadratic regression model showed that the appropriate temperature for growth is between 27 and 28°C.