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Host-specific phenotypic plasticity of the turtle barnacle Chelonibia testudinaria: a widespread generalist rather than a specialist.

Cheang CC, Tsang LM, Chu KH, Cheng IJ, Chan BK - PLoS ONE (2013)

Bottom Line: Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles.Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts.Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles.

View Article: PubMed Central - PubMed

Affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.

ABSTRACT
Turtle barnacles are common epibionts on marine organisms. Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles. It has been questioned why C. patula, being abundant on a variety of live substrata, is almost absent from turtles. We evaluated the genetic (mitochondrial COI, 16S and 12S rRNA, and amplified fragment length polymorphism (AFLP)) and morphological differentiation of C. testudinaia and C. patula from different hosts, to determine the mode of adaptation exhibited by Chelonibia species on different hosts. The two taxa demonstrate clear differences in shell morphology and length of 4-6(th) cirri, but very similar in arthropodal characters. Moreover, we detected no genetic differentiation in mitochondrial DNA and AFLP analyses. Outlier detection infers insignificant selection across loci investigated. Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts. Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles.

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Maximum likelihood (ML) tree of Chelonibia testudinaria and C. patula in this study with sequences of C. testudinaria from Rawson et al. (2003) (GenBank accession nos.: AY174312–16, 24–28, 34–8, 42–46, 58–62) and outgroup C. caretta (FJ385728-30).ML and Bayesian inference (BI) analyses yield the same topology. Bootstrap (1,000 replicates) values for ML (normal) and the posterior probabilities for BI (bold) analyses are indicated at the nodes. (EP: eastern Pacific; WP: western Pacific; A: Atlantic).
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pone-0057592-g004: Maximum likelihood (ML) tree of Chelonibia testudinaria and C. patula in this study with sequences of C. testudinaria from Rawson et al. (2003) (GenBank accession nos.: AY174312–16, 24–28, 34–8, 42–46, 58–62) and outgroup C. caretta (FJ385728-30).ML and Bayesian inference (BI) analyses yield the same topology. Bootstrap (1,000 replicates) values for ML (normal) and the posterior probabilities for BI (bold) analyses are indicated at the nodes. (EP: eastern Pacific; WP: western Pacific; A: Atlantic).

Mentions: Chelonibia testudinaria from the present study, together with those from the Pacific coast of Japan [29], clustered with C. patula (Figure 4). The K2P distances between these three groups were between 0.0042 and 0.0065 (Table 1). Populations of C. testudinaria in the Atlantic Ocean formed a sister clade to the western Pacific populations (Figure 4) and demonstrated K2P distances of 0.1057–0.1066 (Table 1). The eastern Pacific is the most divergent population of C. testudinaria (Figure 4), with K2P distance up to 0.1210 from the other populations (Table 1). Haplotypes within each of the three mitochondrial markers revealed by the TCS analysis did not group together according to species nor locality of populations (Figure 5). All dominant haplotypes could be found in both species as well as in different populations (Figure 5).


Host-specific phenotypic plasticity of the turtle barnacle Chelonibia testudinaria: a widespread generalist rather than a specialist.

Cheang CC, Tsang LM, Chu KH, Cheng IJ, Chan BK - PLoS ONE (2013)

Maximum likelihood (ML) tree of Chelonibia testudinaria and C. patula in this study with sequences of C. testudinaria from Rawson et al. (2003) (GenBank accession nos.: AY174312–16, 24–28, 34–8, 42–46, 58–62) and outgroup C. caretta (FJ385728-30).ML and Bayesian inference (BI) analyses yield the same topology. Bootstrap (1,000 replicates) values for ML (normal) and the posterior probabilities for BI (bold) analyses are indicated at the nodes. (EP: eastern Pacific; WP: western Pacific; A: Atlantic).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585910&req=5

pone-0057592-g004: Maximum likelihood (ML) tree of Chelonibia testudinaria and C. patula in this study with sequences of C. testudinaria from Rawson et al. (2003) (GenBank accession nos.: AY174312–16, 24–28, 34–8, 42–46, 58–62) and outgroup C. caretta (FJ385728-30).ML and Bayesian inference (BI) analyses yield the same topology. Bootstrap (1,000 replicates) values for ML (normal) and the posterior probabilities for BI (bold) analyses are indicated at the nodes. (EP: eastern Pacific; WP: western Pacific; A: Atlantic).
Mentions: Chelonibia testudinaria from the present study, together with those from the Pacific coast of Japan [29], clustered with C. patula (Figure 4). The K2P distances between these three groups were between 0.0042 and 0.0065 (Table 1). Populations of C. testudinaria in the Atlantic Ocean formed a sister clade to the western Pacific populations (Figure 4) and demonstrated K2P distances of 0.1057–0.1066 (Table 1). The eastern Pacific is the most divergent population of C. testudinaria (Figure 4), with K2P distance up to 0.1210 from the other populations (Table 1). Haplotypes within each of the three mitochondrial markers revealed by the TCS analysis did not group together according to species nor locality of populations (Figure 5). All dominant haplotypes could be found in both species as well as in different populations (Figure 5).

Bottom Line: Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles.Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts.Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles.

View Article: PubMed Central - PubMed

Affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.

ABSTRACT
Turtle barnacles are common epibionts on marine organisms. Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles. It has been questioned why C. patula, being abundant on a variety of live substrata, is almost absent from turtles. We evaluated the genetic (mitochondrial COI, 16S and 12S rRNA, and amplified fragment length polymorphism (AFLP)) and morphological differentiation of C. testudinaia and C. patula from different hosts, to determine the mode of adaptation exhibited by Chelonibia species on different hosts. The two taxa demonstrate clear differences in shell morphology and length of 4-6(th) cirri, but very similar in arthropodal characters. Moreover, we detected no genetic differentiation in mitochondrial DNA and AFLP analyses. Outlier detection infers insignificant selection across loci investigated. Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts. Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles.

Show MeSH