sign in sign up
<<
Home , Alpheus armatus, Ancylomenes, Ancylomenes pedersoni, Bartholomea, Bartholomea annulata, Cleaner shrimp

Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93

Contents lists available at SciVerse ScienceDirect

Journal of Experimental Marine Biology and Ecology

journal homepage: www.elsevier.com/locate/jembe

Host selection by the cleaner pedersoni: Do anemone host , prior experience or the presence of conspecific shrimp matter?

Maite Mascaró a,⁎, Lizbeth Rodríguez-Pestaña b, Xavier Chiappa-Carrara a, Nuno Simões a a Unidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Yucatán, México b Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, México D.F. México article info abstract

Article history: In the symbiotic association that exists between (= peder- Received 13 February 2011 soni) and host sea anemones, specificity varies among populations, and shrimp are believed to search among Received in revised form 23 November 2011 different individual hosts for favourable positions from which to attract client fish. Four laboratory-based exper- Accepted 25 November 2011 iments were conducted to test host selection of A. pedersoni between the following: i) annulata Available online xxxx (corkscrew anemone) and gigantea (condy anemone), ii) B. annulata, with or without a conspecific resident, iii) a previously known or unknown B. annulata, and iv) a previously known or unknown C. gigantea. Keywords: Ancylomenes (=Periclimenes) pedersoni Preference (active selection) was distinguished from mere passive association by comparing shrimp acclimation to anemones offered in choice and no-choice (control) situations. The results were analysed using asymmetrical Cleaner shrimp χ2 contingency tables (in each experiment, n=60) where expected frequencies were obtained with maximum likelihood estimators. Shrimp acclimated more frequently to B. annulata than to C. gigantea, but they acclimated Preference similarly to anemones with or without another resident and to those B. annulata and C. gigantea anemones that Sea anemones were familiar rather than unfamiliar. However, none of the χ2 values were statistically significant 2 (χ df = 1 =0.48, 0.19, 0.42, 0.42; overall p>0.45), suggesting that preference may not be responsible for the as- sociation between adult A. pedersoni and its host anemones observed in the field. Differences in the frequency of association may be due to factors other than the active decisions made by shrimp when presented with more than one alternative host. © 2011 Elsevier B.V. All rights reserved.

1. Introduction the degree to which resident shrimp are host-specific varies with both the shrimp and host species and can differ from one population to an- Several species of the shrimp genus Periclimenes establish symbiotic other within the distribution range (Silbiger and Childress, 2008 and relationships with sea anemones, but the costs and benefits of such examples therein). associations are still uncertain (Bauer, 2004; Fautin et al., 1995). Ancylomenes pedersoni (Chace, 1958) (reported as Periclimenes ped- While some studies suggest commensalism where only shrimp obtain ersoni until recently; Okuno and Bruce, 2010) is distributed from Cape protection from predators (Bruce, 1976), other studies consider mutu- Lookout, North Carolina, down the east coast of the United States and alism as the basis for the interaction in which anemones obtain either around the west coast of Florida, to the Bahamas, West Indies, Bonaire, protection from shrimp (McCammon, 2010) or an additional source of Netherland Antilles and Belize (Chace, 1958, 1972; Williams, 1984). nitrogen from shrimp faeces (Spotte, 1996). Field studies report A. pedersoni to be a symbiotic cleaner shrimp Differences in the degree of host specialisation can be mediated by frequently associated with Bartholomea annulata, to a lesser extent habitat use because some of these species are considered to be cleaner with Condylactis gigantea, and occasionally with other anemones shrimp that remove parasites and decayed tissue off of client fish (Chace, 1972; Mahnken, 1972; Silbiger and Childress, 2008; Williams (Kotter, 1997; Limbaugh et al., 1961; Mahnken, 1972; Zhang et al., and Bunkley-Williams, 2000). However, in Quintana Roo, Mexico, 1998). In general, Periclimenes (sensu lato) that do not clean fish are A. pedersoni has never been observed to be associated with C. gigantea considered to be host-specific, whereas cleaner shrimp search among (Campos-Salgado, 2009), although several authors have reported this different anemone species for favourable positions from which to specific association at other locations in the Great Caribbean (Criales attract fish (e.g., Feder, 1966; Guo et al., 1996; Limbaugh et al., 1961; and Corredor, 1977; Mihalik, 1989; Spotte et al., 1991; Wicksten, Nizinski, 1989; Williams, 1984). Moreover, as in other associations, 1995) and the Gulf of México (Sisal Banks and Alacranes Reef; Simoes, N., pers. obs.). There is also considerable variation in the grouping pattern exhib- ⁎ Corresponding author. Tel./fax: +52 988 9120147. ited by cleaner shrimp of the genus Periclimenes. Several authors E-mail address: [email protected] (M. Mascaró). mention that A. pedersoni are often found alone, in pairs, or in groups

0022-0981/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jembe.2011.11.026 88 M. Mascaró et al. / Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93 of 5–6 individuals (Mahnken, 1972; Stanton, 1977). In the Mexican of different sizes and reproductive conditions described for the Mexican Caribbean (Campos-Salgado, 2009; unpublished data), 63% of the Caribbean (Campos-Salgado, 2009), only A. pedersoni (1.5-2.5 cm B. annulata recorded had no A. pedersoni, 21% had 1 individual, 9% had length), B. annulata and C. gigantea (5–10 cm diameter of the oral disc 2 individuals, and 7% had groups of 3–5 shrimp. Groups of more than of completely distended anemones) were used in the experiments. 10 shrimp of different sizes that are associated with only one host The sex of captured shrimp was not recorded, but all individuals were have occasionally been observed (Campos-Salgado, 2009; Wicksten, non-ovigerous. Shrimp were captured using fine nets, and anemones 1995). There have been reports of considerable aggression between were carefully removed from the substratum to minimize damage to individuals competing for favourable positions within a host to obtain and reefs. Taxonomic descriptions by Chace (1972) and food, both under laboratory conditions and in the wild (Mahnken, Gonzalez-Muñoz (2008) were used to correctly identify shrimp and 1972). While these observations suggest that shrimp that are already anemone species, respectively. Captured organisms were individually present in an anemone may constitute an adverse stimulus for other placed in small plastic containers, previously perforated to allow A. pedersoni to acclimate to that particular host, previous residents water exchange. The containers were kept in a large plastic holder could act as positive stimuli and attract more individuals. Huebner with abundant seawater and constant aeration to ensure survival dur- (2010) reported that the number of fish being cleaned at any particular ing transportation to the Unidad Multidisciplinaria de Docencia e Inves- station increased significantly with the number of A. pedersoni associat- tigación, Facultad de Ciencias, Universidad Nacional Autónoma de ed to the host. This suggests an advantage for client fish to stop at anem- México, at Sisal, Yucatán, México where experiments were conducted ones that host several shrimp. However, for such gregarious behaviour from September 2007 to March 2008. An identification code was to constitute an advantage for A. pedersoni,individualshrimpwould assigned to each individual to make it possible to retrieve detailed infor- need to benefit from the aggregation (e.g., if the mean rate of food intake mation about its capture. Hosts and anemones captured at the same per individual shrimp increased in stations with several A. pedersoni location were never used in the same trial to prevent previous contact compared with those with only one or two shrimp). between the host and the shrimp from potentially affecting selective Symbiotic decapods associated with sessile marine macroinverte- behaviour. To comply with statistical independence, individual shrimp brates live in well-established microhabitats (i.e., sessile hosts; Baeza were used only once in the same experiment. Anemones were used and Stotz, 2003), and the shrimp-anemone relationship constitutes an several times in the same experiment, but were isolated for 15 days be- ideal model to study host preference. However, the associations that tween subsequent trials. A. pedersoni that were separated from both are often observed in natural conditions do not necessarily reflect B. annulata and C. gigantea for 15 days have been shown to lose protec- preference for a particular host species or individual because their dis- tion from the nematocysts of these anemones, but re-acclimate if tribution may be the result of ecological factors, such as host abundance, allowed contact with hosts (Rodriguez-Pestaña, 2007). or inter- and intra-specific competition and (Gwaltney and Shrimp and anemones were isolated and maintained in fibre-glass Brooks, 1994; Khan et al., 2003; Silbiger and Childress, 2008) that forces aquaria connected to two separate closed-water recirculation systems residents to associate with less-preferred hosts. Some authors have for a period of 15–45 days prior to the trials. This was performed to established that preference is the outcome of a behavioural choice prevent any chemical contact between the hosts and the anemones that is displayed by an organism (Singer, 2000) and that its adequate during maintenance and to ensure that selection was based on anemo- identification and understanding can only be achieved with appropriate ne characteristics alone. Seawater in both recirculation systems was experimental controls in which the subjects under study are presented kept at 35±1‰ salinity and 25±1 °C using automatic chillers and with no-choice situations (Underwood and Clarke, 2005; Underwood occasional partial water exchanges. In addition, seawater in the anemo- et al., 2004). These authors argue that in testing hypotheses about ne recirculation system was kept at approximately constant concentra- + + -1 - -1 selective behaviour, it is necessary to distinguish active selection or tions of ammonia (NH4 /NH3 : 0 mg L ), nitrates (NO3:5mgL ), - -1 = -1 preference for a particular resource from passive or mechanical selec- nitrites (NO2: 0 mg L ), phosphates (PO4 :0.1mgL ) and pH (8.2), tion that is the result of physical properties, such as prey or habitat which were measured every fifth day using colorimetric methods. Pho- availability (Barbeau and Scheibling, 1994; Jackson and Underwood, toperiod was kept constant at 12 h:12 h, and commercially available, 2006; Underwood et al., 2004). Based on these definitions and this high-intensity lamps for seawater aquaria (10,000 K, DYMAX OB Light- methodological approach, a series of four experiments on the selective ing with two T5 light tubes, white and blue) were used to maintain light behaviour of A. pedersoni were conducted to determine whether the conditions adequate for endosymbiotic microalgae in anemones. Anem- observed patterns of association with its host anemones B. annulata ones were left to attach to small rocks or gastropod shells to facilitate and C. gigantea in the field are the result of a behavioural and active relocation and quick full expansion of their tentacles. Shrimp were fed choice. frozen Artemia spp., polychaetes, penaeid larvae (mysis) and diced mussels ad libitum 3 times a day. Anemones were fed a similar diet 2. Materials and methods every 3 days. We conducted four anemone host choice experiments with A. peder- A. pedersoni (105), B. annulata (76) and C. gigantea (54) were soni (Table 1). The first experiment was intended to test if patterns of captured during several SCUBA expeditions from Puerto Morelos to host specificity can be explained by active selection or preference of Majahual, Quintana Roo from August 2007 to March 2008. Based on the shrimp for B. annulata. The second experiment was designed to the patterns of distribution and the abundance of shrimp and anemones test if the presence of another shrimp of the same species, approximate

Table 1 Choice (CH) and no-choice (NCH1 and NCH2) anemone treatments presented to A. pedersoni during experiments on host-species selection (Experiment 1); selection of B. annulata with vs. without a previous conspecificresident(Experiment 2); selection of previously known vs. unknown B. annulata (Experiment 3); and selection of previously known vs. unknown C. gigantea (Experiment 4). Ba = B. annulata; Cg = C. gigantea.

No choice treatments Choice treatment

NCH1 NCH2 CH

Experiment 1 2 Ba 2 Cg 1 Ba+1 Cg Experiment 2 2 Ba with resident 2 Ba without resident 1 Ba with resident+1 Ba without resident Experiment 3 2 known Ba 2 unknown Ba 1 known Ba+1 unknown Ba Experiment 4 2 known Cg 2 unknown Cg 1 known Cg+1 unknown Cg M. Mascaró et al. / Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93 89 size and reproductive condition (nonovigerous, conspecific shrimp) in- (Underwood and Clarke, 2005). With this procedure, better estimates of cited active selection for that individual anemone. The conspecific frequencies under the null hypothesis were obtained and the effect of a shrimp were acclimated to anemones prior to selection trials and small sample size was reduced (Underwood and Clarke, 2005). In addi- were presented simultaneously with the hosts to the focal shrimp. tion, the sample size of n=60 adequately complied with the Roscoe The third and fourth experiments with B. annulata and C. gigantea, and Byars rule (Zar, 1999), thus ensuring that bias in the contingency respectively, were designed to test whether previous acclimation to a tables and the χ2 used was negligible. particular individual anemone (known anemone) motivated subse- quent active selection for that same individual. The shrimp were accli- 3. Results mated to each anemone one at a time and allowed to interact for at least 24 h, after which the shrimp were separated from each host for Mean duration of selection trials was 4 h±50 min, with 1 h 30 min at least 15 days prior to selection trials. and 6 h 15 min as the minimum and maximum duration, respectively. All four experiments were carried out by presenting each A. peder- No shrimp acclimated to both hosts in any of the experimental trials. soni with the following: i) two similar anemones of a first type (no- choice treatment 1; NCH1), ii) two similar anemones of a second type Experiment 1. The results of the experiment on host species selection (no-choice treatment 2; NCH2), and iii) two different anemones of showed that 39 (65%) A. pedersoni acclimated to one of the anemones types 1 and 2 (choice treatment; CH; Table 1). Care was taken so that present in the aquaria (Fig. 1A), and, overall, more shrimp acclimated individual anemones in each pair were similar in the diameter of the to B. annulata (29) than to C. gigantea (10). However, statistical analysis oral disc, but expansion state of the anemone was not taken into revealed no significant differences between acclimation frequencies to account. Sixty independent and randomly selected shrimp were used B. annulata and C. gigantea between choice and no-choice situations χ2 in each experiment (20 replicatesx3 treatments per experiment). ( df = 1 =0.48; p=0.49; Table 2). This indicated that the difference in Prior to each trial, the corresponding anemones were introduced acclimation of A. pedersoni to the two species of anemones was not into the two furthest ends of a 50×20×20 cm (L×W×D) glass aquar- the result of an active selection. The number of shrimp that did not ac- ium filled with seawater (~20 L). Both seawater and room conditions climate to any of the anemones that were presented within a 7 h period were similar to those used during the maintenance of experimental an- varied between treatments. A relatively high percentage of shrimp imals. After 30 min, aeration was removed, and an individual A. peder- (65%) did not acclimate to C. gigantea even when this species was the soni was introduced into the centre of the aquarium. Aeration was only alternative in the aquaria (Fig. 1A). removed to reduce the influence of the direction of water flow and Experiment 2. The results of the experiment on selection of B. annulata water-borne chemical cues that could affect host selection. The shrimp with or without a previous symbiotic conspecificshowedthat42(70%) were video recorded and allowed to acclimate to any of the alternative of the A. pedersoni acclimated to one of the B. annulata present in the hosts. A shrimp was considered to be acclimated to an anemone when it aquaria (Fig. 1B). Overall, 24 A. pedersoni acclimated to B. annulata remained on top of, among or under (oral Ddisk) the anemone's tenta- that were already hosting a symbiotic shrimp, and 18 A. pedersoni accli- cles or at a distance b3 cm from the most distal portion of the tentacles mated to B. annulata with no shrimp already present. Statistical analysis for at least 1 h. Shrimp that had not acclimated within 7 h to any of the revealed no significant differences between acclimation frequencies to anemones offered were recorded as such and included in the statistical B. annulata with or without a shrimp already present between choice analysis. The criteria to define these terms were taken from Stanton and no-choice situations (χ2 =0.19; p=0.66;Table 2). This there- (1977), Mahnken (1972) and acclimation experiments previously df = 1 by demonstrates that A. pedersoni did not exhibit any preference for B. conducted in our laboratory with these species (Rodriguez-Pestaña, annulata with or without an earlier conspecific resident. The number 2007). A total of 5 experimental aquaria were used, which were fully of shrimp that did not acclimate to any anemone within a 7 h period cleansed with running seawater between trials to prevent any previous in this experiment was similar between treatments, with 35%, 20% treatment from affecting the outcome of the next trial. and 35% in NCH1, NCH2 and CH treatments, respectively (Fig. 1B). To test the hypothesis that A. pedersoni actively selected one of the two alternatives offered in each experiment, the difference in the Experiment 3. The results of the experiment on fidelity to an individ- frequency of shrimp acclimated to the two options in the CH treatment ual B. annulata showed that 40 (66.7%) A. pedersoni acclimated to one of should be greater than that in NCH treatments. If frequencies in the CH the anemones present in the aquaria (Fig. 1C). Of these, 18 shrimp accli- and NCH treatments were similar, then shrimp would acclimate to mated to previously known individuals, and 22 shrimp acclimated to hosts in a similar fashion regardless of whether different alternatives unknown individuals. Statistical analysis of the data revealed no signif- were available. If alternatives were not available, the observed patterns icant differences in acclimation frequencies to either alternative under of association to hosts could not be attributed to the exercise of an active χ2 choice and no-choice situations ( df = 1 =0.42; p=0.52; Table 2). choice. This can also be expressed as: These results showed that A. pedersoni did not exhibit any preference for previously known or unknown individual B. annulata. The number : q1 > q2 Hexp ; of shrimp that did not acclimate to any anemone within a 7 h period p1 p2 was similar between treatments (35%, 30%, and 35%, for NCH1, NCH2, where the null hypothesis is: and CH treatments, respectively; Fig. 1C). Experiment 4. The results of the experiment on fidelity to an individ- : q1 ¼ q2 ; Hnull p1 p2 ual C. gigantea showed that 43 (71.7%) of the shrimp acclimated to one of the anemones present in the aquaria (Fig. 1D). Overall, more A. ped- where q1 and q2 are the proportion of shrimp acclimated to options 1 ersoni acclimated to individual C. gigantea that had previously hosted and 2 in the CH treatment, and p1 and p2 are the proportion of shrimp that shrimp (26), than to anemones with which the shrimp had no acclimated to options 1 and 2 in NCH treatments, respectively. Because previous experience (17). However, differences in acclimation frequen- the options in the NCH treatments were similar, p1 and p2 were cy with both alternatives were similar in choice and no-choice situa- χ2 obtained by adding shrimp that were acclimated to both of the hosts tions ( df = 1 =0.42; p=0.52) thereby demonstrating that offered in NCH1 and NCH2, respectively. Data from each experiment A. pedersoni did not acclimate more frequently to known individuals were analysed by means of χ2 in asymmetrical contingency tables as a result of active selection. The number of shrimp that did not accli- where the observed proportions were used to derive maximum likeli- mate to any of the anemones that were presented within a 7 h period hood estimators for the expected proportions under the null hypothesis varied between treatments. A relatively high percentage of shrimp 90 M. Mascaró et al. / Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93

Fig. 1. Percentage of the shrimp A. pedersoni that acclimated to (A) B. annulata and C. gigantea (Experiment 1), (B) B. annulata with and without a previous resident conspecific shrimp (Experiment 2), (C) previously known and unknown B. annulata (Experiment 3), and (D) previously known and unknown C. gigantea (Experiment 4). No-choice treatments (NCH1, NCH2) and choice treatments (CH) are as described in Table 1. Values are calculated considering the total number of shrimp in each treatment (n=20).

(55%) did not acclimate to unknown C. gigantea, even when these indi- (Fig. 1A). This difference, however, was statistically similar both when viduals were the only alternative in the aquaria (Fig. 1D). shrimp were (CH treatments) and were not presented with a choice of alternative host species (NCH1 and NCH2 treatments) (Table 2). 4. Discussion Thus, there is not enough evidence to confirm that active choice or pref- erence caused the differences in association that were observed in Results of selection trials showed that A. pedersoni acclimated to Experiment 1. certain anemones more frequently than to others (Fig. 1), but no statis- It is often assumed that animals are associated with a particular hab- tical evidence could be found to support that this behaviour was a itat because they prefer it and have rejected others available (Crowe consequence of active choice. Such findings are relevant in that they and Underwood, 1998). However, previous studies on the selective suggest that local ecological factors, rather than behavioural preference, behaviour of a variety of marine invertebrates have stressed the difficul- are responsible for the observed patterns of distribution in these host- ty in distinguishing experimental evidence of preference (also called shrimp associations. active selection) from simple, or even complex patterns of association When offered both anemone species simultaneously (Experiment 1; (also called passive selection) (Chapman, 2000; Underwood et al., CH treatment), more shrimp selected B. annulata than C. gigantea 2004). Some authors maintain that only by comparing the frequency

Table 2 Number of A. pedersoni that acclimated to anemones B. annulata and C. gigantea under different conditions and those that did not acclimate to any of the anemones present in the aquaria during experiments on host-species selection (Experiment 1); selection of B. annulata with vs. without a previous conspecific resident (Experiment 2); selection of previ- ously known vs. unknown B. annulata (Experiment 3); and selection of previously known vs. unknown C. gigantea (Experiment 4). The estimated number of shrimp (maximum likelihood) in each case is shown in parentheses. Choice (CH) and no-choice (NCH1 and NCH2) anemone treatments for all experiments are defined as in Table 1; n=60 replicates (20 individuals per treatment) were used in each experiment.

Did not acclimate

Experiment 1 B. annulata C. gigantea NCH1 17 (17.2) – 3 (2.9) NCH2 – 7 (6.3) 13 (13.7) CH 12 (10.9) 3 (4.0) 5 (5)

Experiment 2 (B. annulata) With resident Without resident NCH1 16 (16.1) – 4 (3.9) NCH2 – 13 (12.7) 7 (7.3) CH 8 (7.3) 5 (5.7) 7 (7)

Experiment 3 (B. annulata) Known Unknown NCH1 13 (12.6) – 7 (7.4) NCH2 – 14 (14.3) 6 (5.7) CH 5 (6.1) 8 (6.9) 7 (7)

Experiment 4 (C. gigantea) Known Unknown NCH1 16 (15.7) – 4 (4.3) NCH2 – 9 (9.6) 11 (10.4) CH 10 (11.2) 8 (6.8) 2 (2) M. Mascaró et al. / Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93 91 distribution of events (e.g., prey consumed, shells taken, hosts chosen, any grooming behaviour or acclimate to that host within the following etc.) under choice and no-choice conditions can passive selection be 24 h (Rodriguez-Pestaña, 2007). Despite these similarities, a greater discarded and active selection be experimentally confirmed as the proportion of shrimp acclimated to B. annulata (80%) than to C. gigantea behavioural cause of the association (Jackson and Underwood, 2006; (20%; Rodriguez-Pestaña, 2007). Both the acclimation experiments by Liszka and Underwood, 1990; Olabarria et al., 2002). This is because Rodriguez-Pestaña (2007) and those described in the present study preference can only be displayed by an individual when it is presented were conducted with shrimp and anemones collected from the Mexican with more than one option (Barbeau and Scheibling, 1994). For exam- Caribbean. These were then kept in laboratory aquaria for periods ple, a symbiotic shrimp that always chooses a live host over an inert 15–45 days prior to the experiments without the presence of client rock does not necessarily indicate preference for the live host if the ex- fish. Consequently, the fact that the A. pedersoni in the present study tent to which the rock constitutes an alternative is not taken into ac- acclimated to most (but not all) of the B. annulata and some of the count. The fact that preference is not corroborated does not imply that C. gigantea that were offered implies that the experimental shrimp pos- there are artificial differences in the frequency of associations that is ob- sessed the physiological (biochemical) and behavioural mechanisms served in the field, and other mechanisms should be put forward to ex- necessary to acquire protection from both anemone species. These plain such differences. By contrast, if preference is mistakenly results strongly suggest that patterns of association observed at any confirmed, then explanations other than those based on behaviour particular site are partly determined by local processes, and care must may be overlooked. be taken when extrapolations are made to other sites within the Previous studies on Periclimenes shrimp have shown that under geographic distribution of the species. laboratory conditions individuals selected those species of host anem- When given a choice, A. pedersoni associated in relatively similar ones with which they were frequently found associated in the field frequencies with individual B. annulata with or without an earlier (Guo et al., 1996; Gwaltney and Brooks, 1994; Khan et al., 2003; conspecificshrimp(Fig. 1B). Moreover, statistical analysis demonstrat- Silbiger and Childress, 2008). It is possible that those laboratory results ed that even small differences in these frequencies were not due to ac- merely confirmed differences in the frequency of association that tive choice (Table 2), suggesting that territoriality in A. pedersoni does depend strongly on local ecological factors and to a lesser extent on not influence host choice through behavioural preference. Even when behavioural traits involving preference because both the relative resources are plentiful, interference between individuals when search- frequencies of association and host species may vary throughout the ing and/or using a resource constitutes evidence of competition distribution range of symbiotic shrimp (Criales, 1984; Guo et al., 1996; (Sheridan et al., 1984) that often leads to the display of agonistic inter- Levine and Blanchard, 1980; Wicksten, 1995). In a field study from actions or territorial behaviours. Isla Contoy to Xcalak on the Caribbean coast of Mexico, Campos- Such behaviour among shrimp in natural conditions has been Salgado (2009) found that 698 of the 704 A. pedersoni recorded were described for A. pedersoni (Mahnken, 1972)andAncylomenes anthophi- associated with B. annulata, and none were found associated with C. lus (Sargent and Wagenbach, 1975) and depends on the sex, reproduc- gigantea. However, A. pedersoni has been reported to associate with C. tive condition and size of individuals occupying a single host gigantea in part of its distribution range (Criales, 1984; Silbiger and (Knowlton, 1980; Mahnken, 1972). A. pedersoni that were used both Childress, 2008; Williams and Bunkley-Williams, 2000). These contrast- as previous residents and focal individuals in the present study ranged ing field results and the lack of an active choice shown in this study from 1.5 to 2.5 cm long and were never ovigerous. While uncontrolled (Table 2; Fig. 1A) indicate that ecological features operating at a local differences in shrimp sex could have affected host selection in scale must be involved in determining the observed patterns of associ- Experiment 2, the lack of significant differences cannot be related to ation in these species. the rather small differences in size and reproductive condition of indi- While both anemone species simultaneously occur at most sites vidual shrimp occurring randomly within the 60 replicate trials. How- along the Caribbean coast of Mexico, their abundance and occurrence ever, it is possible that the influence of territorial behaviour was not vary with depth, substrate depressions, crevices or holes at different evident because the ultimate resource to be defended (client fish) was sections of the reef (i.e., reef lagoon, edge or front) (Campos-Salgado, absent from the aquaria, and the effect of a simultaneous resident in 2009). Moreover, A. pedersoni is mostly found on top or among B. annu- the anemone lacked immediate consequences for the experimental in- lata tentacles (Mahnken, 1972) and moves from between hosts dividual. In addition, it is possible that the conditions of the trials did not (Huebner, 2010; Limbaugh et al., 1961). Such behaviour is explained stimulate competition by interference between shrimp because shrimp by the way in which A. pedersoni search for favourable positions to were fed before the trials and because the maximum number of shrimp clean fish, both within an individual anemone and among anemones in any aquarium was limited to 3. Sargent and Wagenbach (1975) within the same patch (Nizinski, 1989; Williams, 1984). In his study found that A. anthophilus did not exhibit territorial behaviour unless on cleaner shrimp in the Virgin Islands, Mahnken (1972) frequently fish that were ready to be cleaned were introduced into the aquaria. found associations of many A. pedersoni per individual B. annulata in The absence of territorial behaviour can be expected in laboratory con- sandy areas of the reef where there was increased trafficoflargefish ditions where stimuli that induce territoriality have been removed. that were ready to be cleaned. It is possible that on the coast of Quintana Thus, in the future, both field and laboratory-based experiments of Roo, B. annulata is more frequent than C. gigantea in reef areas that are host preference should consider aspects such as predation risk, limiting easily accessed by large fish, hence explaining the pattern of the distri- resources and competition for food. bution of association of A. pedersoni with its hosts in the region. Field studies in the Virgin Islands report the most common associa- A high percentage of shrimp did not acclimate to C. gigantea even tions of A. pedersoni to be in pairs or groups of 5–6individuals when no other alternative was present in the aquaria (Table 2; (Mahnken, 1972), whereas in the Mexican Caribbean cleaner shrimp Fig. 1A). This could be explained if shrimp were insufficiently protected were often found alone or in pairs (30%), and less frequently in groups against the neurotoxins in the nematocysts of C. gigantea, as has been of 3–6 individuals (7%; unpublished data). While the number and size of reported for A. pedersoni with (Gwaltney and symbiotic residents are limited by the number and size of anemone Brooks, 1994). However, previous experiments that compared the accli- hosts (Allen, 1972; Fautin, 1991), the presence of conspecifics on a mation of A. pedersoni to B. annulata and C. gigantea (Rodriguez-Pestaña, host anemone has also been considered to be an attractive incentive 2007) showed that shrimp acclimated to these anemones by displaying for promoting further associations, both during larval settlement and similar exploratory and grooming behaviours, regardless of host reproduction for different taxa (Jensen and Morse, 1984; Knowlton species. Rodriguez-Pestaña also showed that A. pedersoni that had not and Keller, 1986; Sweatman, 1983). A grouping pattern such as this acclimated within 7 h to an individual host of either B. annulata or could be explained if territorial and agonistic behaviours did not result C. gigantea did not make physical contact with the anemone, display in the complete exclusion of subordinate shrimp from the host but in 92 M. Mascaró et al. / Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93 a hierarchical arrangement in which dominant individuals obtain the Program of Marine Sciences and Limnology, National Autonomous most favourable positions within the anemone. Mahnken (1972) University of México. Substantial help on keeping and mainte- observed that the largest individuals were positioned on the tentacles nance of aquarium systems was provided by the late Luis Enrique or near the oral disc of anemones (presumably the most favourable Hidalgo Arcos. We are grateful to Dr Raymond Bauer and the anony- position to attract client fish), while medium and small shrimp mous referees who substantially improved the quality of this manu- occupied positions aligned around the anemone on the nearby sand. script. [RH] Ongoing field experiments of the agonistic behaviour in A. pedersoni of different sizes and reproductive conditions will help to understand the distribution of shrimp on individual anemones. References When given a choice in Experiments 3 and 4, similar numbers of Allen, G.R., 1972. The Anemone : Their Classification and Biology. T. F. H. Publ., cleaner shrimp acclimated to previously known and unknown B. annu- Inc., Neptune City, N. K. 288 pp. lata (Fig. 1C) and C. gigantea,(Fig. 1D; Table 2), indicating that A. peder- Baeza, J.A., Stotz, W., 2003. Host-use and selection of differently colored sea anemones – soni does not exhibit fidelity to individual hosts of these two anemone by the symbiotic crab Allopetrolisthes spinifrons. J. Exp. Mar. Biol. Ecol. 284, 25 39. fi Barbeau, M.A., Scheibling, R.E., 1994. Behavioural mechanisms of prey size selection by sea species. Some symbiotic show lifetime delity to only one star (Asterias vulgaris Verril) and crabs (Cancer irroratus Say) preying on juvenile sea individual host (Hamel et al., 1999; Kropp, 1987), while others move scallops (Placopecten magellanicus) (Gimelin). J. Exp. Mar. Biol. Ecol. 180, 103–136. frequently between individuals of the same species (Correa and Thiel, Bauer, R.T., 2004. Remarkable Shrimp: Adaptations and Natural History of the Carideans. University of Oklahoma. 282 pp. 2003; Patton et al., 1985; Thiel et al., 2003). These results suggest that Bruce, A.J., 1976. and of coral reefs, with special references to commensal- A. pedersoni maintains a symbiotic association with more than one indi- isms. In: Jones, O.A., Endeon, R. (Eds.), Biology and Geology of Coral Reefs. Academic vidual host, a behaviour which may enable it to increase its home range Press, New York, pp. 38–94. fi fi Campos-Salgado, A.I., 2009. Distribución geográ ca y abundancia de las anémonas and bene t from a diversity of positions within the reef in order to (: ) Condylactis gigantea, Bartholomea annulata y sus camarones access more client fish. A similar behaviour has been reported in the pis- simbiontes Periclimenes pedersoni, P. yucatanicus, armatus y Thor amboinensis tol shrimp, , that can mate with more than one female (Crustacea::) en la costa del Caribe Mexicano. Graduate Thesis, Faculty of Sciences, Universidad Nacional Autónoma de México, 126 pp. that is associated with neighbouring B. annulata (Knowlton, 1980). Chace, F.A., 1958. A new shrimp of the genus Periclimenes from the West Indies. Proc. The absence of fidelity would be predicted if A. pedersoni were not Biol. Soc. Wash. 26 (71), 125–132. able to discriminate between two individual hosts of the same species. Chace Jr., F.A., 1972. The shrimps of Smithsonian Bredin Caribbean Expedition with a This would result in similar frequencies of shrimp acclimating to either summary of the west Indian shallow water species (Crustacea: Decapoda: Natantia). Smith. Contrib. Zool 98, 1–165. alternative host, whether these were both known, both unknown or Chapman, M.G., 2000. Poor design of behavioural experiments gets poor results: one was known and one was unknown. In the experiment with B. annu- examples from intertidal habitats. J. Exp. Mar. Biol. Ecol. 250, 77–95. lata, A. pedersoni acclimated to hosts in similar frequencies, irrespective Correa, C., Thiel, M., 2003. Mating systems in caridean shrimp (Decapoda: Caridea) and their evolutionary consequences for sexual dimorphism and reproductive biology. of host treatment (Fig. 1C); however, this was not the case in Rev. Chil. Hist. Nat. 76 (2), 187–203. Experiment 4 with C. gigantea (Fig. 1D). Acclimation is probably related Crawford, J.A., 1992. Acclimation of the shrimp, Periclimenes anthophilus, to the giant to short-term memory because it is a physiological and behavioural , Condylactis gigantea. Bull. Mar. Sci. 50, 331–341. Criales, M.M., 1984. Shrimps associated with coelenterates, echinoderms, and molluscs process mediated by visual and chemical stimuli. Magnussen et al. in the Santa Marta Region, Colombia. J. Crust. Biol. 4 (2), 307–317. (2003) related host fidelity to short-term memory and stated that Criales, M.M., Corredor, L., 1977. Aspectos etológicos y ecológicos de camarones limpia- thresholds to discriminate individuals are determined by the host's dores de peces (Natantia: , Hipplytidae, Stenopodidae). An. Inst. Invest. Marina de Punta Bol. 30, 570–576. attributes that provide visual and chemical information that is retained Crowe, T.P., Underwood, A.J., 1998. Testing behavioural "preference" for suitable micro- in the resident's memory. Anemones used as ‘known’ individual hosts in habitat. J. Exp. Mar. Biol. Ecol. 225, 1–11. the present experiments were separated from their corresponding Fautin, D.G., 1991. The anemonefish symbiosis: what is known and what is not? Symbiosis – residents for 15 days prior to each trial. It is possible that a period of 10, 23 46. Fautin, D.G., Chau-Chih, G., Jiang-Shiou, H., 1995. Costs and benefits of the symbiosis 15 days exceeds the short-term memory span of these shrimp, thus between the anemoneshrimp Periclimenes brevicarpalis and its host Entacmaea precluding individual recognition. In addition, isolated, but otherwise quadricolor. Mar. Ecol. Prog. Ser. 129, 77–84. fed, shrimp could have learned that association with anemones was Feder, H.M., 1966. in the marine environmental. Chapter 7. In: Mark, Henry S. (Ed.), Symbiosis, 1. Academic Press, pp. 327–397. no longer necessary to obtain food. The time needed for A. anthophilus Gonzalez-Muñoz, R., 2008. Anémonas (Anthozoa: Actiniaria, Corallimorpharia y Zoanthi- (Crawford, 1992)andA. pedersoni (Rodriguez-Pestaña, 2007)tolose dea) del Arrecife de Puerto Morelos, Quintana Roo. M. Sc. Thesis, Posgrado de Ciencias protection from the nematocysts of their respective hosts was well del Mar y Limnologia, Universidad Nacional Autónoma de México, 80 pp. Guo, C.C., Hwang, J.S., Fautin, D.G., 1996. Host selection by shrimps symbiotic with sea within 15 days of isolation. However, under similar laboratory condi- anemone: a field survey and experimental laboratory analysis. J. Exp. Mar. Biol. tions, Rodriguez-Pestaña (2007) found that all A. pedersoni that were Ecol. 202, 165–176. separated from both B. annulata and C. gigantea for 15 days Gwaltney, C.L., Brooks, W.R., 1994. Host specificity of the anemoneshrimp Periclimenes pedersoni and P. yucatanicus in the Florida Keys. Symbiosis 16, 83–93. re-acclimated when they were allowed contact with the hosts. Further Hamel, J.F., Ng, P.K.L., Mercier, A., 1999. Life cycle of the pea crab Pinnotheres halingi sp. experiments using shorter separation times are needed to understand nov., an obligate symbiont of the Holothuria scabra Jaeger. Ophelia 50, the role of memory in individual recognition between hosts and 149–175. Huebner, L.K., 2010. The role of host sea anemones in the cleaning mutualism between residents. anemoneshrimp and client fishes. M. Sc. Thesis. Auburn University, USA, 51 pp. Results of all four selection experiments in the present study suggest Jackson, A.C., Underwood, A.J., 2006. Application of new techniques for the accurate that preference is not responsible for the association between adult analysis of choice of prey. J. Exp. Mar. Biol. Ecol. 341 (1), 1–9. Jensen, R.A., Morse, D.E., 1984. Intraspecific facilitation of larval recruitment: gregarious A. pedersoni and its host anemones and that differences in the frequency settlement of the polychaete Phragmatopoma californica (Fewkes). J. Exp. Mar. Biol. of association with B. annulata and C. gigantea are due to factors other Ecol. 83, 107–126. than active decisions made by shrimp when presented with more Khan, R.N., Becker, H.A., Crowther, A.L., Lawn, I.D., 2003. Sea anemone host selection by than one alternative host. However, further investigations on the the symbiotic saddled cleaner shrimp Periclimenes holthuisi. Mar. Freshwater Res. 54, 653–656. three-way interaction between anemones (hosts), cleaner shrimp Knowlton, N., 1980. Sexual selection and dimorphism in two demes of a symbiotic, (residents) and fish (clients) are needed to understand the frequency pair-bonding snapping shrimp. Evolution 34 (1), 161–173. and distribution of such complex assemblages in reef habitats. Knowlton, N., Keller, B.D., 1986. Larvae which fall far short of their potential highly localized recruitment in an alpheid shrimp with extended larval development. Bull. Mar. Sci. 39 (2), 213–223. Acknowledgments Kotter, I., 1997. Larval culture of (de Man 1888), Lysmata debelius (Bruce 1983) (Decapoda: Hippolytidae) and (Decapoda: Stenopodi- dae). M.Sc. University of Bielefeld, Germany. 106 pp. This study was partially funded by grants PAPIITIN228107 and Kropp, R.K., 1987. Descriptions of some endolithic habitats for snapping shrimp PAPIIT-IN216506. LRP carried out MSc studies with the Postgraduate () in Micronesia. Bull. Mar. Sci. 41, 204–212. M. Mascaró et al. / Journal of Experimental Marine Biology and Ecology 413 (2012) 87–93 93

Levine, D.M., Blanchard, O.J., 1980. Acclimation of two shrimps of the genus Periclimenes to Silbiger, N.J., Childress, M.J., 2008. Interspecific variation in anemone shrimp distribution sea anemones. Bull. Mar. Sci. 30, 460–466. and host selection in the Florida Keys (USA): implications for marine conservation. Limbaugh, C., Pederson, D., Chace Jr., F.A., 1961. Shrimps that clean fishes. Bull. Mar. Sci. Bull. Mar. Sci. 83 (2), 329–345. 11, 237–257. Singer, M.C., 2000. Reducing ambiguity in describing plant–insect interactions: “ prefer- Liszka, D., Underwood, A.J., 1990. An experimental design to determine preferences for ence”, “acceptability” and “electivity”.Ecol.Lett.3,159–162. gastropod shells by a hermit-crab. J. Exp. Mar. Biol. Ecol. 137, 47–62. Spotte, S., 1996. Supply of regenerated nitrogen to sea anemones by their symbiotic Magnussen, S., Greenlee, M.W., Aslaksen, P.M., Kildebo, O.O., 2003. High-fidelity perceptu- shrimp. J. Exp. Mar. Biol. Ecol. 198, 27–36. al long- term memory revisited and confirmed. Psychol. Sci. Jan. 14 (1), 74–76. Spotte, S., Heard, R.W., Bubucis, P.M., Manstan, R.R., McLelland, J.A., 1991. Pattern and Mahnken, C., 1972. Observations on cleaner shrimps of the genus Periclimenes. In: Collete, coloration of from the Turks and Caicos Islands, with B., Earle, S. (Eds.), Results of the Tektite Program: Ecology of Coral Reef Fishes: Nat. comments on host associations in other anemones shrimps of the West Indies and Hist. Mus. Los Angeles Co. Sci. Bull., 14, pp. 71–83. Bermuda. Gulf Res. Rep. 8, 301–311. McCammon, A., 2010. Snapping shrimp protect host anemones from predators. M.Sc., Stanton, G., 1977. Habitat partitioning among decapods associated with Lebrunia danae Thesis, Florida Atlantic University, FL. 43 pp. at Grand Bahama. Proc. 3rd. International Coral Reef Symposium. Rosentiel School Mihalik, M.B. 1989. Investigations on symbiosis between shrimp and sea anemones. of Marine and Atmospheric Science, University of Miami, pp. 169–175. Masters Thesis, Florida Atlantic University, FL. 99 pp. Sweatman, H.P.A., 1983. Influence of conspecifics on choice of settlement sites by larvae of Nizinski, M.S., 1989. Ecological distribution, demography and behavioral observations on two pomacentrid fishes (Dascyllus aruanus and D. reticulatus) on coral reefs. Mar. Biol. Periclimenes anthophilus, a typical symbiotic cleaner shrimp. Bull. Mar. Sci. 45, 75, 225–229. 174–183. Thiel, M., Zander, A., Valdivia, A., Baeza, J.A., Rueffler, C., 2003. Host fidelity of a symbiotic Okuno, J., Bruce, A.J., 2010. Designation of Ancylomenes gen. nov., for the ‘Periclimenes porcellanid crab: the important of host characteristic. J. Zool. London 261, 353–362. aesopius species group’ (Crustacea: Decapoda: Palaemonidae), with the description Underwood, A.J., Clarke, K.R., 2005. Solving some statistical problems in analyses of exper- of a new species and a checklist of congeneric species. Zootaxa 2372, 85–105. iments on choices of food and on associations with habitat. J. Exp. Mar. Biol. Ecol. 318, Olabarria, C., Underwood, A.J., Chapman, M.G., 2002. Appropriate experimental design 227–237. to evaluate preferences for microhabitat; an example of preferences by species of Underwood, A.J., Chapman, M.G., Crowe, T.P., 2004. Identifying and understanding microgastropods. Oecologia 132, 159–166. ecological preferences for habitat or prey. J. Exp. Mar. Biol. Ecol. 300, 161–187. Patton, W.K., Patton, R.J., Barnes, A., 1985. On the biology of Gnathophylloides mineri,a Wicksten, M.K., 1995. Within-species variation in Periclimenes yucatanicus (Ives), with shrimp inhabiting the sea urchin Tripneustes ventricosus.J.Crust.Biol.5(4),616–626. taxonomic remarks on Pedersoni Chace (Crustacea: Decapoda: Caridea: Palaemonidae). Rodriguez-Pestaña, L. 2007. Aspectos sobre la selección de hospedero entre el camarón Proc. Biol. Soc. Wash. 108 (3), 458–464. simbionte anemonal Periclimenes pedersoni y sus anémonas hospederas Bartholomea Williams, A.B., 1984. Shrimps, Lobsters, and Crabs of the Atlantic Coast of the Eastern annulata y Condylactis gigantea. Tesis de Maestría. Posgrado en Ciencias del Mar y United States, Maine to Florida. Smith. Inst. Press, Washington, D. C.. 550 pp. Limnología, Universidad Nacional Autónoma de México, 70 pp. Williams Jr., H., Bunkley-Williams, L., 2000. Experimental refutation of the ease of associate Sargent, R.C., Wagenbach, E., 1975. Cleaning behavior of the shrimp, Periclimenes change by the , Periclimenes yucatanicus (Decapoda, Palaemoni- anthophilus Holthuis and Eibl-Eibesfeldt (Crustacea: Decapoda: Natantia). Bull. dae), new false-coral associates for the Pederson cleaner shrimp, P. pedersoni, and gener- Mar. Sci. 25, 466–472. al abundance of associations for the both shrimps. Crustaceana 73 (4), 503–511. Sheridan, P.F., Browder, J.A., Powers, J.E., 1984. Ecological interactions between penaeid Zar, J.H., 1999. Biostatistical Analysis, Fourth ed. Prentice Hall Inc., New Jersey, USA. 663 pp. shrimp and bottomfish assemblages. In: Gullan, J.A, Rothschild, B.J. (Eds.), Penaeid Zhang, D., Lin, J., Creswell, R.L., 1998. Mating behaviour and spawning of the banded Shrimps: Their Biology and Management. Fishing New Books Ltd., Farnham, G.B, coral shrimp Stenopus hispidus in the laboratory. J. Crust. Biol. 18, 31–45. pp. 235–250.