AQUATIC ANIMAL REPORTS (AQAR)

Centrocestus formosanus (Heterophydae) infection in ornamental fish Cyprinus carpio var. koi (Cyprinidae): in Mexico center

Elideth ZAMORA ROA — 2025-08-27

Parasite problems in ornamental fish represent a health risk that results in economic losses in the sector, including infections by Centrocestus formosanus, which have been identified as diseases that affect fish health and also have zoonotic potential. Due to the sanitary importance of this trematode, this study aimed to report the presence of C. formosanus in ornamental fish in Tulancingo de Bravo, Hidalgo. 36 aquarium koi carp (Cyprinus carpio Koi) were acquired for parasitological analysis in search of ecto- and endoparasites. A water sample was also collected to determine water quality parameters using a Hanna® colorimetric kit (Hannapro, SA de CV © 2022, CDMX, Mexico). The fish analyzed showed metacercariae cysts in the gill filaments, corresponding to C. formosanus with a prevalence of 5.5 %, while the water quality showed pH (10.84± 0.05), nitrite (28± 0.00), nitrate (17.72± 0.00) and CO₂ (23± 2.64) values indicating poor water quality. These findings suggest that poor water quality may be associated with the presence of C. formosanus. This study presents the first report of C. formosanus in ornamental fish in the municipality of Tulancingo de Bravo, serving as a tool for future monitoring and management of parasite loads.

Storage stability of an ornamental fish diet enriched with palmyrah fruit (Borassus flabellifer) pulp

Sutharshiny SATHYARUBAN — 2025-08-27

The ornamental fish industry depends on high-quality diets for health and growth. Many available or formulated feeds degrade over time, reducing nutritional value, palatability, and cost-effectiveness. Over ten months, this study investigates the storage stability of an ornamental fish diet enriched with a novel feed additive, Palmyrah fruit (Borassus flabellifer) pulp. The quality of the experimental feed was assessed in terms of its nutritional composition, microbial properties, and cost-effectiveness, which were compared with the commercial diet. Users’ perception of the experimental diet was assessed using a questionnaire. Statistical analysis was performed using Minitab Statistical Software 2021. The results showed that the experimental feed is not harmed by aflatoxin contamination (20 μg kg^-1) and total bacterial count (1.5 x 10³ cfu g^-1). The protein content of experimental and commercial feeds remained constant for ten months (42.17 ± 0.06 and 40.53 ± 0.37, respectively), although the fat content of the experimental feeds did not differ significantly (P < 0.05) at the three storage periods. A downward trend in the proportion of all fatty acids in both feed types was observed after ten months of storage. Despite a rise in moisture, it remained under 10%, preventing microbial growth. The stakeholders have been receptive to the experimental feed for ornamental fish, which is 22 times more cost-effective than commercial feed on a small scale. Our findings indicate that the experimental feed remains of stable quality for ten months of storage under room temperature (25 - 33 ºC), which offers a sustainable and cost-effective solution for the aquaculture industry.

Recent record and some biological characteristics of painted eel (Echelus myrus Linnaeus.1758) in the Northern Aegean Sea, Türkiye

Yusuf ŞEN — 2025-08-27

A specimen of the painted eel Echelus myrus (Linnaeus, 1758) was incidentally caught on May 24, 2025, by Serdar BAYRAM from the Darpane fishing vessel with a bottom longline from the northern Aegean Sea, Türkiye. The individual measured 546 mm in total length and weighed 98.25 g. In addition to these, other morphometric measurements were taken, and the meristic characteristics were recorded. The specimen was identified as a female with mature gonads (ripe stage). Oocyte diameters ranged from 0.63-1.22 mm with the mean of 0.90±0.015 mm. The stomach content of Echelus myrus revealed only the fragment of cuttlefish bait associated with the longline hook and line. These findings contribute to the limited existing knowledge of the biological characteristics Echelus myrus in by providing an additional record from Türkiye. This study also includes the recent observation of rarely recorded Echelus myrus in the northern Aegean Sea, Türkiye.

Socioeconomic and cultural factors affecting fish consumption: The case of Bozdoğan

Hülya ÖZTÜRK — 2025-08-27

This study aims to examine fish consumption preferences in the Bozdoğan district of Aydın province and to identify the social, cultural, and economic factors influencing these preferences. Data obtained from a 25-question survey conducted face-to-face with 120 randomly selected people were analyzed using SPSS 21. The mean age of the participants was 40.88±11.29, the number of members in the family was 3.57±1.16, and the average monthly income was 50.803±25.327. As a result of the analyses, no significant differences were found in annual fish consumption amounts according to age, gender, education, marital status, and income group variables (p>0.05). Red meat was the most preferred type of meat consumption among the participants, with fish meat coming in third. In Bozdoğan, fish consumption increases in winter and decreases in summer, becoming more limited to special occasions. While fish is readily available, the majority find it moderately or expensively priced. Nutritional value and taste are paramount in fish consumption; fresh fish is preferred, and grilling, pan-frying, and oven-baking are the most common methods. Farmed rainbow trout was the most favored species, whereas offshore fish led the rankings among habitat-based groups. While fish is generally procured from fishermen, the vast majority do not catch fish. While consumption frequency varies, many people consume fish regularly. Sea bream, anchovy, and trout stand out as the most delicious fish, while salmon is the most expensive and anchovy the most affordable. Most participants believe that increasing income will increase fish consumption.

Abundance and spatial distribution of the fish eggs and larvae of european sprat, Sprattus sprattus in the Sea of Marmara, Türkiye.

İsmail Burak DABAN — 2025-08-27

European Sprat, Sprattus sprattus (Linnaeus, 1758), is recognized as one of the most representative small pelagic fish species in the Black Sea and the Sea of Marmara (SoM). Scientific data on the early life characteristics of Sprat stocks in the SoM have been insufficient. In the present study, we aimed to elucidate the mean abundance of fish eggs and larvae, as well as their spatial and temporal variations in the SoM. To achieve this, three ichthyoplankton surveys were conducted in December 2021, January 2022, and March 2022 across 32 equally distributed stations covering the entire Marmara Sea. Sprat eggs and larvae were collected using vertical plankton tows with a WP-2 type plankton net equipped with a 300 μm mesh. Among all winter spawners in this study, Sprat was the most abundant fish species for both eggs and larvae, comprising 90.1% and 61.9% of the total abundance, respectively. The mean Sprat abundance per unit area (n/10 m²) was determined to be 713.8 n/10 m², with mean prelarvae abundance at 43.5 n/10 m² and postlarvae at 16.9 n/10 m². A total of 80.3% of the fish eggs, with a mean of 1719.9 n/10 m², and 73.6% of the total larvae abundance, with 133.6 n/10 m², were observed in February. Three primary spawning grounds were identified: the Karacabey Floodplain area (S18), Büyükçekmece shores (S23-S26), and Tekirdağ shores (S8), with larval movement observed from the northern to the southwestern regions and possibly from S18 to the southwestern part.