50 SEPTEMBER 2023 • WORLD AQUACULTURE • WWW.WAS.ORG and UV filtration. Culture conditions in the aquaria were maintained at a temperature of 24 - 27º C, a salinity of 33 - 35 PSU, gentle aeration, a 12:12 photoperiod, and 100 percent O2 saturation. Juveniles were fed with Artemia nauplii ad libitum twice a day. Every day until day 30, three juveniles were sampled, anesthetized with a 4 percent phenoxyethanol solution, and fixed in a 4 percent paraformaldehyde solution and stored in 2-5 ml Eppendorf tubes. Juveniles were weighed to the nearest 0.0001g and photographed with a digital camera (SONY a-6000). Eleven body segments were measured in every photograph using Photo Image analysis software1. These measurements included the head length (HL), the distance from the tip of the snout to the mid-point of the cleithral ring; the trunk length (TrL), the curved distance from the mid-point of the cleithral ring to the mid-point of the last Study Description In the present report, we evaluated the growth patterns and development of juvenile H. ingens kept under culture conditions in a commercial farm during the first 30 days of development. This report could provide relevant information for the planning and improvement of feeding protocols, and the appropriate time to propose a modification or adaptation of culture conditions to attend to the biological characteristics of seahorses. Also, it may contribute to the body of knowledge regarding the biological capabilities and ecological traits to be considered in restocking programs for this species. Pacific seahorse juveniles were obtained from one spawn of H. ingens broodstock held under culture conditions in the commercial farm INGENS Cultivos Marinos in Mazatlán, Mexico (Figure 2). Juveniles were maintained in 100 L glass tanks. Seawater was treated with mechanical (5μm), biological, TABLE 1. Growth coefficients (b) of different body segments during the juvenile stages of the Pacific seahorse Hippocampus ingens. In parenthesis is the SL interval for each stage. HL = head length; TrL = trunk length; TaL = tail length; DL = dorsal fin length; CH = coronet height; SnL = snout length; SH = snout height; OD = orbital diameter; PO = postorbital distance; HH = head height. Segment Stage I (7.5-10.0 mm) Stage II (10.1-26.0 mm) Stage III (26.1-41.0 mm) HL 1.02 0.84 0.86 TrL 0.62 1.00 1.00 TaL 1.27 1.08 1.08 DL 0.87 0.90 0.90 CH 1.22 0.92 0.92 SnL 1.20 0.72 0.30 SH 0.68 0.85 0.85 OD 0.84 0.92 1.08 PO 0.99 0.99 0.99 HH 0.96 0.87 1.05 FIGURE 3. Body dimensions measured during the early development of H. ingens. 1 = head length; 2 = trunk length; 3 = tail length, the standardlength SL resulted by the summation of 1, 2, and 3; 5 = dorsal fin length; 6 = coronet height; 7 = snout length; 8 = snout height; 9 = orbital diameter; 10 = postorbital distance; 11 = head height. Photo by R. P.
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