The use of morphometric analysis to predict the swimming efficiency of two Neotropical long-distance migratory species in fish passage

Abstract

This study investigated the external body morphology (based on morphometric data) and the swimming efficiency in fish passages (based on the ascent time in a fish ladder) of two Neotropical long-distance migratory species. The fish were collected in the fish ladder of the Porto Primavera Hydroelectric Power Plant (known as Engenheiro Sergio Motta), upper Paraná River, Brazil. The species differ in several morphometric ratios related to swimming performance. Prochilodus lineatus exhibited a higher muscle ratio and caudal fin length ratio. However, Leporinus elongatus showed higher values for the fineness ratio, a higher length from snout to pectoral fin base ratio, and a higher caudal peduncle depth factor. Although both species show good swimming performance, the characteristics listed above may enable L. elongatus to apply greater power and propulsion, allowing it to reach a high swimming speed and to exhibit greater efficiency than P. lineatus. Leporinus elongatus moves faster than P. lineatus and has a lower mean ascent time (1.39 hours) than P. lineatus (3.76 hours). Prochilodus lineatus would require a somewhat longer time to pass through the fish ladder.Este estudo investigou a relação entre a morfologia externa do corpo (baseado em dados morfométricos) e eficiência de natação em passagem para peixes (baseado no tempo de ascensão em uma escada para peixes) de duas espécies neotropicais migradoras de longas distâncias. Os peixes foram coletados na escada para peixes da Usina Hidrelétrica de Porto Primavera (conhecida como Engenheiro Sérgio Motta), alto Rio Paraná, Brasil. As espécies diferem em algumas razões morfométricas referentes ao desempenho de natação: Prochilodus lineatus apresentou valores mais elevados para razão muscular e razão do comprimento da nadadeira caudal. No entanto, Leporinus elongatus apresentou valores mais elevados para razão fineza, para razão do comprimento do focinho à base da nadadeira peitoral e para fator de largura do pedúnculo caudal. Embora ambas as espécies tenham um bom desempenho natatório, essas características podem permitir a L. elongatus aplicar uma maior potência e propulsão, permitindo atingir velocidades de natação elevadas e apresentar uma melhor eficiência em relação a P. Lineatus. Leporinus elongatus movimenta-se mais rápido, com um tempo médio de ascensão (1,39 horas) inferior ao de P. lineatus (3,76 horas), que requer um tempo um pouco maior para passar através da escada para peixes.

Passage Performance of Technical Pool-Type Fishways for Potamodromous Cyprinids: Novel Experiences in Semiarid Environments

“…Other studies for the close relative Barbus barbus in the Swiss Rhone River showed analogous transit time to ours in pool-type fishways [64]. In general, fish size influenced the time needed to overcome the fishway, with longer times for the smaller fish, which is consistent with other fishway evaluations [36][37][38]65]. Longer fish had more body mass, as well large fins, which are very important as sources of propulsive forces to cross velocity barriers faster [65,66].…”

Passage Performance of Technical Pool-Type Fishways for Potamodromous Cyprinids: Novel Experiences in Semiarid Environments

“…Other studies for the close relative Barbus barbus in the Swiss Rhone River showed analogous transit time to ours in pool type fishways [62]. In general, fish size influenced on the time needed to overcome the fishway, with longer times for the smaller fish, which is consistent with other fishway evaluations [35][36][37]63]. Longer fish has more body mass, as well large fins that are very important as propulsive forces sources to cross velocities barriers faster [63,64].…”

Fish passages in South America: an overview of studied facilities and research effort

“…A smaller number addressed mechanism questions, which investigated how passage is affected by operation (e.g., Pompeu, Martinez, 2005), environmental variables (e.g., Fernandez et al, 2007b;Pereira-Assis et al, 2009a), and swimming ability (e.g., Santos et al, 2007;Assumpção et al, 2012;. The fact that just a few papers addressed physiology and consequence questions is more troubling because these approaches provide essential information for management plans; efficiency and mechanism questions cannot, alone, determine management success and the impact of FPF on conservation.…”