Role of coral-derived chemical cues in microhabitat selection by settling Chromis viridis

Abstract

Insight into the mechanisms that underlie settlement and recruitment is important for our understanding of the demography and ecology of coral reef fish and the biology of their coral host. Current knowledge of larval behaviour leading up to settlement is rather meager, and is mostly derived from controlled experiments under artificial conditions. However, it has been shown that presettlement juvenile fishes use acoustic and olfactory cues to locate the reef and, together with visual cues, to choose their first habitat in the reef. Chromis viridis (Pomacentridae) also use chemical and physical cues to locate the coral colonies on which they settle. Moreover, they appear to consistently and preferentially utilize some, but not other, conspecific colonies. To further evaluate the cues involved in microhabitat choice at settlement, we used in situ manipulation in which water from Acropora spp. coral colonies with positive settlement histories (SH+) was transferred to colonies with negative settlement histories (SH-) and vice versa. By closely monitoring settlement to manipulated and non-manipulated colonies, we found that at least 2 different water-borne cues are informing micro-habitat selection by C. viridis. Water transferred from SH-to SH+ A. hyacintus colonies was found to discourage settlement in the SH+ colonies. On the other hand, water transferred from SH+ to SH-A. eurystoma colonies encouraged settlement in the SH-colonies. These findings show that dissolved coral-derived cues dictate the fishes' settlement decisions, which raises an intriguing question as to the information content of these cues and their evolutionary context. KEY WORDS: Settlement · Coral reef fish · Odour Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 409: [181][182][183][184][185][186][187] 2010 aid in identifying and locating conspecifics (Sweatman 1988, Lecchini et al. 2005a.In a previous study (Ben-Tzvi et al. 2008), we have shown that settling Chromis viridis (Cuvier) prefer to settle with conspecific adults within Acropora spp. colonies (see also Lecchini et al. 2005b). However, not all colonies housing adults received settlers, whereas some colonies that were not inhabited by adults did receive settlers. This may not be surprising if it was not for the fact that the same colonies were consistently selected or rejected over 2 major settling events in 2004 and 2005. Although these data suggest that settling with conspecifics may not be as important as originally thought, it is not clear what drives C. viridis settlers to prefer specific colonies (whether inhabited by conspecifics or not) over others.Scleractinian corals are known to be a critical settlement habitat for many coral reef fishes, of which many are not strictly coral-dependent as adults (Jones et al. 2004, Wilson et al. 2006, Pratchett et al. 2008). Thus it is important to understand why fish select specific coral colonies and not others. Since no physical parameters were found to explain the pattern of col...

Glass‐Eel‐Stage American Eels Respond to Conspecific Odor as a Function of Concentration

“…The glass eel washings also elicited consistent directional movements toward the odor sources based on qualitative observations. These results are consistent with how the conspecific cueing hypothesis is presented in other species, whereby Sea Lampreys, salmonids, and pomacentrids preferred movement toward or settlement in areas containing higher concentrations of conspecific odor (Wagner et al 2009;Ben-Tzvi et al 2010;Nordeng and Bratland 2010;Lecchini and Nakamura 2013). This further substantiates conspecific cueing as a possible mechanism for migration coordination in American Eels.…”

“…Spawning migrations of Sea Lampreys Petromyzon marinus have conformed to predictions consistent with the conspecific cueing hypothesis: adult Sea Lampreys migrating upstream consistently prefer locations with higher concentrations of cues from resident larvae (Wagner et al 2009). Some salmonids have been shown to use conspecific chemical cues during their return migrations to natal rivers (Nordeng and Bratland 2010), and the larvae of multiple pomacentrid species also use such cues when moving into settlement areas on coral reefs (Ben-Tzvi et al 2010;Lecchini and Nakamura 2013). Given that American Eels migrate thousands of kilometers to reach inland waters and that conspecific cueing is present among evolutionarily distant species, American Eels may also use conspecific cues to coordinate their movements.…”

Polarized Light Sensitivity and Orientation in Coral Reef Fish Post-Larvae

“…Moreover, they have been shown to possess sensory capabilities that could locate distant targets for settlement (olfactory: e.g. [6] , [7] , [8] , [9] ; auditory: e.g. [10] , [11] ).…”

Terrestrial chemical cues help coral reef fish larvae locate settlement habitat surrounding islands

“…Regardless of larval duration, suitable adult habitat must be located at the conclusion of the larval stage. Settlement-stage larvae are thought to use a variety of settlement cues to locate suitable habitat, for example, chemical cues given off by living substrates (e.g., algae Steinberg and de Nyes 2002 ; Williamson et al 2000 ; coral Ben–Tzvi et al 2010 ) and conspecifics (e.g., barnacles Thiyagarajan 2010 ; fish Atema et al 2002 ; Kingsford et al 2002 ; Lecchini et al 2005 ). Olfactory stimuli are recognized as an important cue for habitat location in diadromous organisms; with studies conducted on eels, lamprey, and fish identifying odor cues as important components for these migratory organisms ( McCleave and Jellyman 2002 ; Hale et al 2009 ; Vrieze et al 2010 ).…”