Using mariculture as a breeding site: reproduction of <em><em>Hypleurochilus fissicornis</em></em> (Actinopterygii: Blenniidae)

Abstract

Summary:Mariculture in estuaries provides substrate for colonization by fouling organisms, thus attracting small cryptic fish species hitherto unknown in this environment. The blenny Hypleurochilus fissicornis is one of the species that is associated with this new system and is found in high abundance in bivalve farming. To understand the reproductive strategy that this species uses in this new environment, we collected specimens monthly in a mariculture on the southern coast of Paraná State (Brazil). After obtaining morphometric data, we removed gonads to determine sex and maturity stage. Gonads were weighed and analysed histologically. Oogenesis showed the same pattern as in other teleosts, but spermatogenesis showed a very complex dynamics. The spawning is multiple and synchronous between sexes, lasting eight months (May to December) and peaking in winter. Hypleurochilus fissicornis was reproductively successful using the mariculture as a breeding site. The species has a variety of tactics to protect its offspring (e.g. batch spawning, long reproductive period, reduced L 50 , parental care and a reproductive peak in winter).Keywords: gametogenesis; histology; reef fish; parental care.El uso de la maricultura como sitio de reproducción: reproducción de Hypleurochilus fissicornis (Actinopterygii: Blenniidae)Resumen: La práctica de la maricultura en estuarios porporciona el sustrato necesario para la colonización de organismos incrustantes, los cuales atraen a pequeños peces crípticos desconocidos hasta la fecha en este ambiente. El blénido Hypleurochilus fissicornis es una de las especies asociadas a estos nuevos sistemas, encontrándose en elevada abundancia junto al cultivo de bivalvos. Con el objeto de entender la estrategia reproductiva que esta especie usa en su nuevo ambiente, se muestrearon mensualmente especímenes en una instalación de maricultura en la costa sur del estado de Paraná (Brazil). Después de obtener los datos morfométricos, las gónadas fueron extraídas para determinar el sexo y el estado de madurez. Las gónadas fueron pesadas y analizadas histológicamente. La ovogénesis presentó el mismo patrón que otros teleosteos, mientras que la espermatogénesis presentó una dinámica compleja. La puesta es múltiple y sincrónica entre sexos, extendiéndose durante ocho meses (de mayo a diciembre), con un pico de puesta en invierno. Hypleurochilus fissicornis tuvo una reproducción exitosa empleando las instalaciones de maricultura como zona de cría. Dicha especie presentó una variedad de tácticas para proteger su descendencia (p.ej. desove en lotes, largos periodos de reproducción, L 50 reducida, cuidado parental y pico de puesta invernal). Editor: E. Mañanos.

Seasonal and ontogenetic changes in the diet of blennyHypleurochilus fissicornis: An estuarine mariculture as a model of the reef environment

“…This consumption can occur when the male (who performs parental care in nests) either recognises unviable eggs and ingests them in order to vacate space for a new female to lay more healthy eggs, or to avoid infection in viable eggs (Kraak, ). This assumption is plausible since that consumption occurred principally in winter, and the reproductive peak of H. fissicornis occurs at this time (Possamai & Fávaro, ). Furthermore, other Blenniidae species were not observed in the oyster farm during the sampling period.…”

“…Seasonality determination was based on abiotic variables values (for more details see Possamai & Fávaro, ), and follow: Autumn (May 2013, April 2014 and May 2014), winter (June 2013, July 2013 and August 2013), spring (September 2013, October 2013 and November 2013) and summer (December 2013 and January 2014). For ontogenic shift analysis, the individuals were classified into three length classes, by the L 50 of species (Possamai & Fávaro, ). The classes were juvenile (0–2.1 cm: all individuals unable to reproduce), transition (2.2–5.8 cm: at least 50% of individuals able to reproduce) and adults (>5.8 cm: all individuals able to reproduce).…”

“…Mariculture structures offer a substrate for fouling organisms, such as corals, bryozoans, sponges and echinoderms, which modify the natural environment and begin to mimic a natural reef environment (Freitas & Velastin, ; Rocha, Kremer, Baptista, & Metri, ; Thrush & Dayton, ), attracting various species of fish, such as H. fissicornis . This blenny is abundant in South Brazilian maricultures (Freitas & Velastin, ; Gerhardinger, Hostim‐Silva, & Barreiros, ), where they find refuge and utilise the area for reproduction (Possamai & Fávaro, ). Therefore, as this artificial environment seems to concentrate these organisms, its use in obtaining biological information of H. fissicornis is a good model to approximate the natural reef.…”

Seasonal composition, abundance and biomass of the subestuarine fish assemblage in Solís Chico (Río de la Plata estuary, Uruguay)

“…In contrast to the expected, these species were not registered in adjacent sub-estuaries and they are little cited for the Uruguayan coast. These species have some common aspects, e.g., small size, bottom dwelling habits, parental care, spawning of few eggs that adhere to the substrate (Acha, 1994;Bruno et al, 2011;García et al, 2005;Mantero et al, 2006;Possamai and Fávaro, 2015) and use of vegetated areas of the Atlantic Ocean, usually in shallow coastal areas and in estuarine waters. The biology of these species remains unknown along the Uruguayan coast and there are only a few records of them (Acuña-Plavan et al, 2010;Machado, 2013;Retta et al, 2006).…”

“…On the other hand, passive gears, such as gill nets allowed the capture of larger species than those caught by seine netting. This can be related to movement and habitat use by fish species, where certain specimens escape more easily the trawl or tend to move to deeper estuarine areas (Potter and Pawson, 1991;Rozas and Minello, 1997;Elliott and Hemingway, 2002). The use of different gears increases the capture efficiency of fish allowing the collection of a more diverse fish assemblage, indicating that is important to consider the capture of each gear type separately (Cowley and Whitfield, 2001).…”