Genetic diversity and population structure of two South American marine gastropods, Crepipatella dilatata and C. fecunda (Gastropoda: Calyptraeidae): Distinct patterns based on developmental mode

Figures & data

Table I. Genetic diversity estimates of C. dilatata and C. fecunda. N refers to the number of individuals sampled, S is the number of segregating sites, H is the number of haplotypes, and for all populations refers to unique haplotypes. Hd is the haplotype diversity and π is the nucleotidic diversity, both with standard deviation in parenthesis. *Significant values at p < 0.05. NA, not applicable

Species	Population	Coordinates	N	S	H	Hd	π	R2	Fu & Li's D	Tajima's D
C. dilatata
	Corral	39°51′S; 73°26′W	19	1	2	0.386 (0.173)	0.00419 (0.0019)	0.1455	0.1393	−1.230
	Quempillén	41°52′S; 73°44′W	24	7	2	0.159 (0.092)	0.00226 (0.0013)	0.1309	1.2870	−1.265
	Puerto Madryn	42°46′S; 64°36′W	13	24	7	0.795 (0.109)	0.01220 (0.0036)	0.1482	−0.6814	−0.9566
	Coquimbo	29°59′S; 71°19′W	7	6	5	0.714 (0.121)	0.00694 (0.0013)	0.2044	1.4625*	2.032*
	All populations		63	35	14	0.807 (0.033)	0.01079 (0.0016)	0.0994	−1.6500	−0.9211
C. fecunda
	Aucho	42°04′S; 73°23′W	15	8	6	0.571 (0.149)	0.00220 (0.00086)	0.1691	−1.7360	−1.7438
	Chinquihue	41°36′S; 73°05′W	15	7	6	0.705 (0.113)	0.00207 (0.00059)	0.1505	−2.1200	−1.5620
	Melinka	43°48′S; 73°54′W	10	6	5	0.756 (0.131)	0.00230 (0.00068)	0.1776	−1.5100	−1.4928
	Metri	41°32′S; 72°42′W	16	7	7	0.825 (0.066)	0.00276 (0.00054)	0.1485	−1.6105	−1.2547
	Yaldad	43°08′S; 73°44′W	25	8	8	0.637 (0.105)	0.00216 (0.00058)	0.1305	−1.0819	−1.5765
	Ancon	11°46′S; 77°10′W	2	1	2	–	–	NA	NA	NA
	Santa María	12°25′S; 76°46′W	3	0	1	–	–	NA	NA	NA
	All populations		86	18	18	0.675 (0.052)	0.00231 (0.00032)	0.0951	−2.9516*	−1.9800*

Figure 1. Map of the Chilean and Argentinean coasts showing the sampling locations of animals used in this study. 1, Coquimbo; 2, Corral; 3, Chinquihue; 4, Metri; 5, Quempillén; 6, Aucho; 7, Yaldad; 8, Melinka; 9, Puerto Madryn. Ancon and Santa María locations from Perú are not shown, as such sequences were obtained from GenBank.

Table II. Distribution of haplotypes per locality of C. dilatata.

Haplotype	Corral	Quempillén	Coquimbo	P. Madryn	Total
H1	1				1
H2	18				18
H3		21			21
H4			1		1
H5			2		2
H6			1		1
H7		3	2		5
H8			1	6	7
H9				2	2
H10				1	1
H11				1	1
H12				1	1
H13				1	1
H14				1	1

Table III. Distribution of haplotypes per locality of C. fecunda

Haplotype	Aucho	Chinquihue	Melinka	Yaldad	Metrí	S. María	Ancon	Total
H1	10	8	5	15	5	3	1	47
H2	1							1
H3	1	1	1		1			4
H4	1	3	2	3	5			14
H5	1	1			1			3
H6	1							1
H7		1						1
H8		1						1
H9			1	2	1			4
H10			1					1
H11					2			2
H12					1			1
H13				1				1
H14				1				1
H15				1				1
H16				1				1
H17				1				1
H18							1	1

Figure 2. Bayesian tree representing the relationships between C. fecunda and C. dilatata populations. Numbers above the branches represent bootstrap support value and Bayesian posterior probabilities. Numbers in parenthesis indicate the number of individuals sharing the respective sequence.

Figure 3. Median-joining network representing the relationships among haplotypes of Crepipatella dilatata (A) and Crepipatella fecunda (B). Small black circles indicate median vectors (Bandelt et al. 1999). Circle size is proportional to haplotype frequencies, with the smaller circle representing one sample. Numbers at the branches represent the number of mutations separating the haplotypes if greater than one.

Figure 4. Mismatch distributions observed (Obs) for (A) Crepipatella dilatata and (B) Crepipatella fecunda. The expected (Exp) frequency is based on a sudden population expansion model. Goodness-of-fit of the observed versus the theoretical mismatch distribution was tested using the sum of squared deviations (SSD).

Table IV. Summary of SAMOVA for C. dilatata. The k-values represent number of groups hypothesized. *p-value is < 0.05

k	Structure tested	F CT value
2	Group 1: Puerto Madryn	0.6170*
	Group 2: Corral, Quempillén, Coquimbo
3	Group 1: Puerto Madryn	0.5885*
	Group 2: Coquimbo
	Group 3: Corral, Quempillén

Table V. Summary of SAMOVA for C. fecunda. The k-values represent number of groups hypothesized. p-value is < 0.05

k	Structure tested	F CT value
2	Group 1: Chinquihue	0.04066
	Group 2: Aucho, Melinka, Metri, Yaldad, Santa María, Ancon
3	Group 1: Melinka, Yaldad, Santa María, Ancon	0.05468
	Group 2: Aucho
	Group 3: Chinquihue, Metrí
4	Group 1: Metrí	0.07068
	Group 2: Chinquihue
	Group 3: Aucho
	Group 4: Melinka, Yaldad, Santa María, Ancon
5	Group 1: Melinka, Santa María, Ancon	0.09512
	Group 2: Metrí
	Group 3: Aucho
	Group 4: Chinquihue
	Group 5: Yaldad
6	Group 1: Santa María, Ancon	0.18935
	Group 2: Metrí
	Group 3: Aucho
	Group 4: Chinquihue
	Group 5: Yaldad
	Group 6: Melinka

Table VI. Results of analysis of molecular variance (AMOVA) for each species of Crepipatella

Species	Level	d.f.	Sums of squares	Variance components	% variance	p-value	Mode of development
C. dilatata	Among populations	3	12.813	0.27294	56.86	<0.001	Intracapsular
	Within populations	59	12.219	0.20710	43.14
C. fecunda	Among populations	6	33.651	0.11683	2.67	<0.5	Pelagic
	Within populations	79	336.605	4.26082	97.33

Bandelt , HJ , Forster , P and Röhl , A. 1999 . Median-joining networks for inferring intraspecific phylogenies . Molecular Biology and Evolution , 16 : 37 – 48 .

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