Association behaviour of the self‐fertilizing Kryptolebias marmoratus (Poey): the influence of microhabitat use on the potential for a complex mating system

Abstract

Preliminary observations were conducted to identify conspicuous body postures and movements of males and hermaphrodites in the mangrove killifish Kryptolebias marmoratus. These behaviours were used quantitatively to examine the social interactions for experimental pairings of K. marmoratus of different sexual states (i.e. simultaneous hermaphrodite and male) in an aquarium with an open-water area and simulated crab burrows. This allowed observation of behaviours that could not be observed in the field. Kryptolebias marmoratus, regardless of sexual state and experimental treatment, spent 40% of the time in the burrow. Hermaphrodites exhibited a preference for associating with males rather than other hermaphrodites. The observed complexity of displayed behaviours and interactions between paired conspecifics indicate that K. marmoratus has a rich repertoire of social behaviour not predicted for a strictly selfing species. Also, land crab burrows play an important role in their social interactions.

Choosy Males Could Help Explain Androdioecy in a Selfing Fish

“…The preference of K. marmoratus hermaphrodites for males over hermaphrodites is in accordance with previous behavioral observations of this species, and it has been suggested that this preference is related to outcrossing (Martin 2007). Our results showed that hermaphrodites chose males over other hermaphrodites when they were able to see and smell the stimulus fish but also when provided only with scented water, suggesting that hermaphrodite K. marmoratus can distinguish the sex of their conspecifics based on olfactory cues alone.…”

“…Displaying a high level of aggression toward other males seems a normal behavior of the species (Martin 2007;Molloy et al 2011). However, in contrast to the seemingly undiscriminating hermaphrodites, males showed strong preferences between genetically (microsatellite and MHC) similar and dissimilar hermaphrodites, spending significantly greater proportions of time with the genetically dissimilar than with the more closely related hermaphrodites in both visual trials (79.0% vs. 21.0%) and olfactory trials (72.3% vs. 27.8%).…”

Inbred and furious: negative association between aggression and genetic diversity in highly inbred fish

“…) Kryptolebias marmoratus . In contrast, hermaphrodite‐male aggression appears to be less frequent (Martin ). Although male aggressiveness in K. marmoratus seems to be uncorrelated with individual genetic diversity (Molloy et al .…”

Population genetics and evolution of the mangrove rivulus Kryptolebias marmoratus, the world's only self‐fertilizing hermaphroditic vertebrate

“…Both of these features, which appear to be unique traits among all vertebrate animals, add to the list of biological superlatives for K. marmoratus. Harrington's (1961) discovery of hermaphroditic selfing in K. marmoratus, plus Kallman & Harrington's (1964) report that highly selfed laboratory lines of this species could be highly homozygous, researchers began to use K. marmoratus as a model species for experimental studies in many areas of biology including: developmental biology (Vogelbein et al, 1987;Grageda et al, 2004), behaviour (Hsu & Wolf, 1999Earley et al, 2000;Martin, 2007;Earley & Hsu, 2008;Luke & Bechler, 2010), ecology (Abel et al, 1987;Davis et al, 2003), ecotoxicology (Koenig & McLean, 1980;Davis, 1984Davis, , 1988Lin & Dunson, 1993;Lee et al, 2008), oncology (Koenig & Chasar, 1984;Park & Kim, 1984;Thiyagarajah & Grizzle, 1986;Courtney & Fournie, 1988;Grizzle & Thiyagarajah, 1988;Park et al, 1990Park et al, , 1993Park et al, , 1994Park & Lee, 1992;Goodwin & Grizzle, 1994a, b, c;Lee et al, 1994Lee et al, , 1995Couch, 1995;Thiyagarajah et al, 1995) and physiology (Grizzle & Thiyagarajah, 1987;Heath et al, 1993;Frick & Wright, 2002;Litwiller et al, 2006;Ong et al, 2007). As described below, however, an important caveat sometimes applies to the findings that emerge from such experimental studies.…”