Coral Reef Degradation Differentially Alters Feeding Ecology of Co-occurring Congeneric Spiny Lobsters

Abstract

Caribbean coral reefs are undergoing massive degradation, with local increases of macroalgae and reduction of architectural complexity associated with loss of reefbuilding corals. We explored whether reef degradation affects the feeding ecology of two co-occurring spiny lobsters: Panulirus guttatus, which is an obligate reef-dweller, and Panulirus argus, which uses various benthic habitats including coral reefs. We collected lobsters of both species from the back-reef zones of two large reefs similar in length (∼1.5 km) but differing widely in level of degradation, at the Puerto Morelos Reef National Park (Mexico). We measured the carapace length (CL) and weight (W) of lobsters, estimated three condition indices (hepatosomatic index, HI; blood refractive index, BRI; and W/CL ratio), and analyzed their stomach contents and stable isotope values (δ 15 N and δ 13 C). All lobsters tested negative for the presence of the virus PaV1, which can affect nutritional condition. Stomach contents yielded 72 animal taxa, mainly mollusks and crustaceans, with an average of 35 taxa per species per reef, but with much overlap. In P. guttatus, CL, HI, BRI, and W/CL did not vary with reef, but mean isotopic values did. The isotopic niche of P. guttatus showed little overlap between reefs, reflecting differences in local carbon sources and underlining the habitat specialization of P. guttatus, which exhibited a higher trophic position on the more degraded reef. Overall, the trophic position of P. guttatus was higher than that of P. argus. In P. argus, none of the variables differed between reefs and the isotopic niche was wide and with great overlap between reefs, reflecting the broader foraging ranges of P. argus compared to P. guttatus. Additional isotopic values from 16 P. argus caught at a depth of 25 m in the fore reef suggest that these larger lobsters forage over different habitats and have a higher trophic position than their smaller conspecifics and congeners from the back reef. The feeding ecology of P. argus appears to be less influenced by coral reef degradation than that of P. guttatus, but our results suggest a buffering effect of omnivory against habitat degradation for both lobster species.

35 años de cambio en densidad y biomasa del megazoobentos del golfo de Batabanó, Cuba, e implicaciones para la langosta, Panulirus argus (Decapoda: Palinuridae)

“…Sin embargo, otros organismos de eslabones tróficos subsecuentes, como los depredadores de langosta, podrían llegar a ser impactados. La langosta P. argus es considerada un mesodepredador omnívoro que forma parte de la dieta de varias especies de interés económico o ecológico como pargos, chernas, pulpos, morenas y tiburones (Cruz et al, 1990;Briones-Fourzán et al, 2019). Estas especies podrían presentar variaciones en su crecimiento y hasta en sus patrones de abundancia y distribución, a causa de variaciones significativas en el megazoobentos que constituye alimento para las langostas.…”

Do ecological characteristics drive the prevalence of Panulirus argus virus 1 (PaV1) in juvenile Caribbean spiny lobsters in a tropical reef lagoon?

“…Later, the subadults (~50 to 80 mm CL) start migrating to coral reefs, which the adults (>80 mm CL) inhabit [2]. P. argus are omnivorous mesopredators and play an important ecological role in Caribbean coral reefs systems [3][4][5], but they are also susceptible to parasites and diseases [6]. For example, they are hosts to Panulirus argus virus 1 (PaV1), the first known naturally occurring virus of a lobster.…”

Tasa de depredación de Panulirus argus (Decapoda: Palinuridae) sobre moluscos gastrópodos en dos zonas pesqueras al sur de Cuba

“…Asimismo, investigaciones sobre la alimentación natural de P. argus han aportado información sobre su dinámica poblacional y han permitido establecer su conducta alimentaria nocturna, su función como mesodepredador omnívoro y su amplio espectro trófico (Phillips et al 2013, Blamey et al 2019, Briones-Fourzán et al 2019. Entre los organismos que integran la dieta de las langostas, moluscos y crustáceos han sido descritos como grupos principales (Colinas-Sánchez & Briones-Fourzán 1990, Herrera et al 1991, Martínez-Coello et al 2015.…”