Neonatal nutritional strategy of a viviparous elasmobranch with extremely low reproductive output

Author(s)

Rangel, Bianca de Sousa ^[1] ; Hussey, Nigel Edward ^[2] ; Niella, Yuri ^[3] ; Martinelli, Luiz Antonio ^[4] ; Gomes, Aline Dal'Olio ^[1] ; Moreira, Renata Guimaraes ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biociancias, Lab Metab & Reprod Organismos Aquat, Dept Fisiol, Rua Matao, Travessa 14, 321 Cidade Univ, BR-05508090 Sao Paulo, SP - Brazil

^[2] Univ Windsor, Dept Biol Sci, Windsor, ON N9B 3P4 - Canada

^[3] Macquarie Univ, Dept Biol Sci, N Ryde, NSW 2109 - Australia

^[4] Univ Sao Paulo, CENA, Dept Ecol Isotop, BR-13416000 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: MARINE ECOLOGY-PROGRESS SERIES; v. 638, p. 107-121, MAR 19 2020.
• Web of Science Citations: 0

Abstract

Throughout evolutionary history, elasmobranchs have developed diverse reproductive strategies. Little focused work, however, has addressed how neonatal nutritional state is affected by differing degrees of maternal investment associated with these markedly different reproductive strategies. To investigate the effect of maternal investment on the nutritional quality of pups during the early life history of an extremely viviparous elasmobranch, quantitative biomarker analysis including lipids, fatty acids and stable isotopes was conducted. Using the cownose ray Rhinoptera bonasus (histotrophic viviparous) as a model, we found that pups were initially born in a positive nutritional state, enriched in physiologically important essential fatty acids and nitrogen and carbon stable isotope values (delta N-15 and delta C-13), a result of maternal intrauterine transfer. A systematic decrease in some fatty acids and delta N-15 values, as well as a decrease in cholesterol with growth, confirmed that these substrates were derived from maternal resources and used in initial metabolic processes following birth. An observed increase in condition factor, plasma essential fatty acids and triglyceride:cholesterol ratio with increasing body size identified a progression towards successful independent foraging with pups not displaying marked nutritional deficiency or fasting phases. Our multi-tracer approach allowed the identification of 2 size classes of young rays (<50 and <70 cm disc width) that displayed distinct physiological states. Since prenatal maternal investment is critical for offspring condition and to promote successful foraging post birth, understanding the trophic ecology and physiological state of pups during their first year is critical to guide management and conservation within nursery grounds. (AU)

• FAPESP's process: 16/09095-2 - Lipids and stable isotopes as maternal investment and neonatal nutritional strategies indicators in histotrophic stingrays
• Grantee: Bianca de Sousa Rangel
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/16320-7 - Impacts of climate/environmental change on the fauna: an integrative approach
• Grantee: Carlos Arturo Navas Iannini
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants