Reproductive behaviour and concurrent sound production of Gulf grouper Mycteroperca jordani (Epinephelidae) at a spawning aggregation site

Abstract

The reproductive and acoustic behaviours of Gulf grouper Mycteroperca jordani were studied at a spawning aggregation site in the southern Gulf of California, México. In May 2015–2017, divers located and surveyed a spawning aggregation site within Cabo Pulmo National Park. Adult M. jordani conformed to a lek mating system in which large males formed territories over sand adjacent to a rocky reef that were spatially segregated from smaller females outside of courtship and spawning periods. Females moved into male territories during evening hours to spawn. Male courtship behaviours targeted a single female, included head shakes and burst rises and preceded pair spawning prior to sunset. Males and females displayed three shared colour phases, but four phases were sex‐specific. During evening hours, courtship and spawning, both sexes exhibited sexual dichromatism concurrent with reproductive behaviours. The pair‐spawning mating system and observations of bimodal size distributions by sex support previous claims of protogyny in the species. Males produced sounds during territorial patrols, courtship and spawning rushes, which corroborated the importance of acoustic communication within the behavioural repertoire associated with spawning. Long‐term acoustic monitoring revealed increases in total sounds detected day−1 from March through June with diel increases (e.g., evenings) that may be indicative of the spawning season. Observations of spawning on 12 consecutive evenings in May 2017 coupled with extended periods of sound production suggest that spawning does not follow a lunar rhythm. This first description of the mating system and sounds of the endangered M. jordani facilitates future development of seasonal and areal protections to restore and manage the species.

Aggregation site fidelity and movement patterns of the protected marine predator giant sea bass (Stereolepis gigas)

“…Results from this study indicated there was no significant difference in hourly residency of fish based on lunar phase as fish were detected during all hours of night across all lunar phases. GSB may be comparable to grouper and snapper species in the Gulf of California that spawn across variable lunar phases, with the large Gulf grouper (Mycteroperca jordani) and leopard grouper (M. rosacea) showing no significant differences in spawning across lunar phases (Erisman et al 2007;Rowell et al 2019). It is possible that abundance and densities of GSB at Catalina are too low to support consistent spawning aggregations, regardless of lunar phase, temperature, or location.…”

“…Although sex of tagged GSB was not assessed in this study nor could it be assessed through visual observation, fish with the shortest distance traveled during the spawning season may have been gravid females that spent most of their time close to spawning aggregation sites to conserve energy for reproduction (i.e., egg production [ Table 2]). However, male gulf groupers, a species of comparable size and range, form leks with dominant males maintaining territories during aggregation spawning while females swim long distances in search of mates (Rowell et al 2019). Although such leks may not seem beneficial for non-resource-based mating systems like broadcast spawning in aggregations (Borgia et al 1979), GSB may exhibit this behavior.…”

Red hind Epinephelus guttatus Vocal Repertoire Characterization, Behavior and Temporal Patterns

“…The females kept in captivity had abdomens that remained distended throughout the experiment, and no eggs were observed in the tank. Since no spawning was detected in captivity it remains unknown if any sounds are produced by Red Hind during gamete release, although this has been demonstrated for the Gulf Grouper (Rowell et al 2019). In Atractoscion nobilis (White Seabass) there is also an association between sound production (drumrolls and thuds) and spawning (Aalbers and (Lobel 1992, Mann andLobel 1995).…”

“…The CAS produced by Red Hind are of low frequency (50-450 Hz) and occur during the spawning aggregation, associated with reproductive behaviors and male displays towards males and gravid females (Mann et al 2010). Visual observations, coupled with passive acoustic recordings have been used to categorize sounds associated with behavioral displays by Nassau Grouper (Schärer et al 2012a), Mycteroperca jordani (Gulf Grouper; Rowell et al 2019), Mycteroperca bonaci (Black Grouper;Schärer et al 2014), Mycteroperca venenosa (Yel-lowfin Grouper;Schärer et al 2012b), Epinephelus polyphekadion (Camouflage Grouper;Jublier et al 2020), Epinephelus marginatus (Dusky Grouper;Bertucci et al 2015) and Epinephelus morio (Red Grouper;Nelson et al 2011), with the latter using lek-like systems of reproduction.…”

Passive monitoring of phenological acoustic patterns reveals the sound of the camouflage grouper, Epinephelus polyphekadion

“…This type of information, which includes understanding the phenology of reproducing species using this pass, is thus essential for management actions that will secure the long-term health and persistence of local grouper populations (Mourier et al, 2019). Within the Epinephelidae, acoustic signals have been associated with courtship behaviour and are likely to be related to the spawning activity of many species, including Epinephelus guttatus (the red hind) (Mann, Locascio, Schärer, Nemeth, & Appeldoorn, 2010), Epinephelus itajara (the goliath grouper) (Mann, Locascio, Coleman, & Koenig, 2009), Epinephelus marginatus (the dusky grouper) (Bertucci, Lejeune, Payrot, & Parmentier, 2015), Epinephelus morio (the red grouper) (Nelson, Koenig, Coleman, & Mann, 2011), Epinephelus striatus (the Nassau grouper) , Mycteroperca bonaci (the black grouper) (Schärer, Nemeth, Rowell, & Appeldoorn, 2014), Mycteroperca jordani (the Gulf grouper) (Rowell, Aburto-Oropeza, Cota-Nieto, Steele, & Erisman, 2018), and Mycteroperca venenosa (the yellowfin grouper) . To our knowledge, however, vocalizations have not been assessed for any Pacific grouper species to date, including the camouflage grouper.…”