Latitudinal variation in the reproductive cycle of two bivalves with contrasting biogeographical origin along the Humboldt Current Upwelling Ecosystem

Abstract

SUMMARY:Argopecten purpuratus (Lamarck, 1819) and Mesodesma donacium (Lamarck, 1818) are bivalves that inhabit the Humboldt Current Upwelling Ecosystem. They have contrasting biogeographical origins, suggesting that their responses to exogenous factors should differ. Using circular statistics, we examine synchrony/asynchrony in the reproductive cycle between populations of each species. The results indicate that there is reproductive asynchrony in both species along their distributional range. However, there was synchrony for A. purpuratus in several location-pairs, including Paita-Chimbote, Chimbote-Callao, Callao-Pisco and Pisco-Antofagasta. For M. donacium, there were only two synchronic groups: Camaná-Capellanía-Mehuín and Hornitos-Peñuelas-Longotoma-La Ligua-Cucao-Quilanlar. A. purpuratus showed gametogenenic activity throughout the year. In contrast, M. donacium showed strong seasonality, with gametogenesis in winter and spawning in spring/summer. In conclusion, the patterns observed for these sympatric species suggest that on a large scale the reproductive cycles follow the expected patterns for the contrasting biogeographic origin of each species, so it could be argued that they are modulated by endogenous factors. However, at a local scale, the reproductive cycles of these species show variation, likely determined by local oceanographic or hydrographic processes.Keywords: Mesodesma donacium, Argopecten purpuratus, synchronic reproduction, gametogenesis, exogenous factors, circular statistics. RESUMEN: Variación latitudinal del ciclo reproductivo de dos bivalvos con orígenes biogeográficos contrastantes a lo largo del ecosistema de afloramiento de la Corriente de Humboldt. -Argopecten purpuratus (Lamarck, 1819) y Mesodesma donacium (Lamarck, 1818) son moluscos bivalvos endémicos del sistema de afloramiento de la Corriente de Humboldt pero tienen orígenes biogeográficos opuestos. Por tanto, se esperaría que los factores exógenos afectaran sus ritmos biológicos diferencialmente, entre ellos sus ciclos reproductivos. Mediante análisis de distribución circular se evaluó el sincronismo/asincronismo en ciclos reproductivos entre poblaciones de cada especie. Los resultados indican que existe asincronía reproductiva en ambas especies a lo largo de su distribución. Sin embargo para A. purpuratus se encontró varios pares de localidades sincrónicas: Paita-Chimbote; Chimbote-Callao; Callao-Pisco y Pisco-Antofagasta, y para M. donacium se dieron dos grupos sincrónicos, el primero entre las poblaciones de Camaná, Capellanía y Mehuín; y el segundo grupo entre Hornitos, Peñuelas, Longotoma, La Ligua, Cucao y Quilanlar. A. purpuratus presentó actividad gametogénica continua. En contraste, M. donacium presentó una marcada estacionalidad, con gametogénesis durante invierno y desoves durante primavera y/o verano. En conclusión, los patrones observados para ambas especies simpátricas sugieren que, a gran escala el ciclo reproductivo sigue los patrones esperados para el origen biogeográfico contrastante de cada especie, por...

Seasonal variability of emerging invertebrate assemblages in a sheltered soft-bottom sublittoral habitat

“…Along the central-south coast of Peru and northern Chile, permanent upwelling changes only incrementally in magnitude during the austral spring and summer (Echevin et al, 2008;Thiel et al, 2007). This pattern contrasts with the strong seasonal upwelling changes in other coastal regions located at the northern (~3°S) and southern (~36°S) extremes of this ecosystem (Chavez et al, 2008;Thiel et al, 2007), and with other coastal systems at similar latitude (Carstensen et al, 2010;Uribe et al, 2012). Seasonal variability in the structure of invertebrate assemblages in this ecosystem appears habitat specific.…”

The Decreasing Availability of Settlement Surfaces Affects the Transition From Larvae to Early Recruitment of the Scallop Argopecten purpuratus Through El Niño and La Niña Episodes

“…Populations of A. purpuratus typically display outbreaks during exceptionally strong El Niño episodes, resulting from faster recovery between spawning events, increased larval production, increased settlement of larvae and increased survival rate and somatic production of juveniles (Illanes et al, 1985;Wolff, 1987;Cantillánez et al, 2005;Wolff et al, 2007). These changes seemingly herald responses of a relict of tropical Miocene fauna that evolved in the cold Humboldt Current System but retained warm water characteristics because recurrent El Niño episodes (Wolff, 1987;Uribe et al, 2012;Riascos et al, 2017). Therefore, it is surprising that larval abundance of A. purpuratus increased only slightly during El Niño 1997-1998 ( Figure 5A).…”

Spatial variation in reproduction in southern populations of the New Zealand bivalvePaphies ventricosa(Veneroida: Mesodesmatidae)

“…Examples are found in a range of bivalve species (Sastry 1979), including Mesodesmatidae, in which Uribe et al (2012) noted significant reproductive asynchrony in populations of M. donacium along the 4000-km long Humboldt Current upwelling ecosystem. P. ventricosa spans 12°of latitude (1350 km), and whilst the cycles are broadly similar, the reproductive cycles of P. ventricosa appear more pronounced in the southern population compared with those at its northern extent (Redfearn 1974).…”

“…Indeed, for M. donacium, latitudinal variation in reproductive cycles has been attributed to a range of factors in addition to temperature, including localised upwelling and changes in salinity and runoff (Uribe et al 2012). Few studies have considered the effects of day length on reproductive cycles in bivalves as it is often difficult to separate from seasonal temperature changes (Gosling 2004), but it is worth noting that seasonal changes in day length are more pronounced at the southern location (from 8 h 34 min to 15 h 50 min, seasonally) compared with the north (from 9 h 34 min to 14 h 36 min, seasonally).…”

“…Of interest in this study is the family Mesodesmatidae (Bivalvia: Veneroida), in which the reproduction has been described in a small number of species including the Australian Donacilla cuneata (Roberts 1984), Asian Coecella chinensis (Kim et al 2013), the South American Mesodesma donacium (Peredo et al 1987;Riascos et al 2009;Uribe et al 2012) and Mesodesma mactroides (Herrmann et al 2009), and the tropical species Atactodea striata (Baron 1992). Reproduction in New Zealand mesodematids, all in the genus Paphies, has been described for P. ventricosa (Redfearn 1974), P. australis (Hooker & Creese 1995), Paphies donacina (Marsden 1999) and Paphies subtriangulata (Grant & Creese 1995).…”