Spatial and temporal distribution, size composition, and abundance of oval squid, Sepioteuthis lessoniana (Lesson 1830) in the coastal waters of Bolong, Zamboanga City, Philippines.

Abstract

The study was conducted in the coastal waters of Bolong, Zamboanga City, Philippines purposely to determine the spatial distribution of Sepioteuthis lessoniana in relation to the depth of water and temporal distribution in relation to lunar phase using size composition and catch per unit effort (CPUE) data. Two sampling stations were established, namely, shallow-water station (Station 1) and deep-water station (Stations 2). Twenty units of squid traps were utilized in the study; ten of which were set in Station 1 and the other ten in Station 2. The traps were constructed using bamboo and green polyethylene netting. Instead of bait, coconut spikelet was placed inside the trap to lure squids. A motorized banca was used to set and haul the traps in the two sampling stations. Although hauling was done daily, sampling is scheduled only 12 times a month with three samplings per lunar phase. Catches were segregated according to sampling stations and lunar phases. Results of the study revealed that the squids caught in deeper waters were significantly larger than those caught in shallow waters, and that females dominated the shallow waters while males dominated the deeper waters. Furthermore, the catch during Full Moon was significantly higher than the catch of the other three lunar phases (p<0.05) with highest CPUE recorded in Station 2 during Full Moon (0.352 kg trap-1 day-1).