Feeding strategies of the ocean white fish (Caulolatilus princeps) and white spotted sand bass (Paralabrax albomaculatus) inside the Galapagos Marine Reserve

Photo: ©slebris / iNaturalist

Abstract
Understanding the diet of two demersal species, the ocean white fish (Caulolatilus princeps) and white spotted sand bass (Paralabrax albomaculatus) provides insights into the trophic strategies they have evolved to co-exist in rocky reefs and soft bottom habitats in the Galapagos Marine Reserve (GMR). We applied two complementary techniques (stomach content and stable isotopes analysis) to determine the trophic habits between species, and categories (sex, life stages and seasons). Sampling was carried out in several sites of fishing importance within the GMR between 2017 and 2018, obtaining 254 stomachs and 58 muscle samples for C. princeps, and 14 stomachs and 34 muscle samples for P. albomaculatus. Trophic spectrum (diet composition), of both predators contained pelagic and benthic prey. The slender anchovy (Anchoa ischana) was the most important prey for C. princeps with no significant differences in the diet between sex, life stages or seasons (p > 0.05); while the most important prey for P. albomaculatus was the threadfin bass (Pronotogrammus multifasciatus). The δ13C and δ15N signatures were significantly different among species (tvalue = 11.81, p < 0.05 and tvalue = 4.67, p <0.05, respectively) suggesting differences in the carbon source (i.e., feeding areas) as well as the preference for different trophic levels (i.e., different prey). Intraspecific analysis in C. princeps showed no differences within sex, life stage and seasons (p > 0.05). Feeding strategies were similar for both predators, with a reduced trophic niche and high variability between preys consumed. This work provides baseline information on two species of ecological and commercial importance within the GMR and highlights the value of trophic studies to generate useful information for an ecosystem-based fisheries management.

Read the article in the link: https://doi.org/10.1016/j.rsma.2024.103530

Recent Posts

Scroll to Top

In 2022, the Galapagos Science Center (GSC) and the broader UNC & USFQ Galapagos Initiative will celebrate its 10th Anniversary. We are proud to announce the World Summit on Island Sustainability scheduled to be held on June 26–30, 2022 at the Galapagos Science Center and the Community Convention Center on San Cristobal Island.

The content of the World Summit will be distributed globally through social media and results documented through papers published in a book written as part of the Galapagos Book Series by Springer Nature and edited by Steve Walsh (UNC) & Carlos Mena (USFQ) as well as Jill Stewart (UNC) and Juan Pablo Muñoz (GSC/USC). The book will be inclusive and accessible by the broader island community including scientists, managers, residents, tourists, and government and non-government organizations.

While the most obvious goal of organizing the World Summit on Island Sustainability is to celebrate the 10th Anniversary of the GSC and the UNC-USFQ Galapagos Initiative, other goals will be addressed through special opportunities created as part of our operational planning of the World Summit.

For instance, we seek to elevate and highlight the Galapagos in the island conservation discourse, seeking to interact with other island networks in more obvious and conspicuous ways to benefit the Galapagos Islands, the UNC-USFQ Galapagos Initiative, and the world. We will seize the opportunity to further develop the I2N2 – International Islands Network-of-Networks. Further, we wish to highlight and emphasize multiple visions of a sustainable future for the Galapagos Islands and we cannot do this alone. Therefore, engaging the Ecuadorian Ministry of Environment, the Ministry of Tourism, the Government Council of Galapagos, the Galapagos National Park, and local Galapagos authorities, including government and non-government organizations and local citizen groups, is imperative.

The Galapagos Science Center on San Cristobal Island, Galapagos

Borrowing from Hawaii’s and Guam’s Green Growth Program and the Global Island Partnership, we wish to examine existing global programs that emphasize island sustainability and their incorporation into life, policies, and circumstances in the Galapagos Islands. We will also seek to enhance our connections with the institutional members of our International Galapagos Science Consortium and expand the Consortium through the recruitment of other member institutions. We will also work to benefit islands and their local communities by working with citizen groups as well as important NGOs who seek to improve the natural conditions in the Galapagos and diminish the impact of the human dimension on the future of Galapagos’ ecosystems.

Lastly, we will use the World Summit to benefit UNC & USFQ and our constituencies through a strong and vibrant communication plan about the World Summit, creating corporate relationships as sponsors, identifying funding goals through donors, and benefiting our study abroad program for student engagement in the Galapagos Islands. We plan to develop and issue a Galapagos Sustainability Communique after the World Summit that includes the vision and insights of all its participants for a sustainable Galapagos with applicability to global island settings.

We are eager to hear your perspective and have you join us at the World Summit on Island Sustainability!