Comparing the sensitivity of two cogeneric ascidian species to two plastic additives: Bisphenol A and the flame retardant tris(chloro-propyl)phosphate

Figures & data

Figure 1. Morphological evaluation of TCPP’s effects on Ciona robusta development. Morphology of control (A–C) and treated (D–G) larvae. (A) Control larva developed in in 0.1% DMSO in ASWH. (B) Magnification of the trunk of a control larva in which the otolith (Ot) and the ocellus (Oc) are observable as well as the three anterior papillae (*). (C) magnification of the tail of a control in which epidermis (e), muscle (m) and notochord (n) are visible; (D, E) malformed larva developed in 25 µg/mL TCPP; (F, G) magnification of malformed larvae displaying a large ovoid cell (arrow) at tail bend point. Scale bars: A, D, E = 100 µm; B, C, F, G = 50 µm  .

Figure 2. Effects of TCPP exposure on the embryonic development of Ciona robusta. (A) Percentages of normal, malformed and dead larvae of C. robusta exposed to TCPP. Differences from control; the number of asterisks indicates the level of significance: *p < 0.05, **p < 0.001, ***p < 0.0001. (B) TCPP dose–response curves for mortality and malformations in C. robusta. EC₅₀ and LC₅₀ values were calculated using probit models.

Figure 3. Morphological evaluation of the effects of BPA exposure on Ciona robusta (A–F) and C. intestinalis (G–L) development. (A, G) controls; (B–F) and (H–L) BPA. Scale bar = 100 µm.

Figure 4. Effects of BPA exposure on embryonic development of Ciona intestinalis and C. robusta. (A) Percentages of normal, malformed and dead larvae exposed to different concentrations of BPA in C. intestinalis. Differences from control: ***p < 0.001. (B) Dose–response curves for mortality in C. intestinalis and C. robusta. (C) Dose–response curves for malformations in C. intestinalis and C. robusta. EC₅₀ and LC₅₀ values were calculated using probit models.

Table I. Percentages of normal, malformed and dead larvae of C. intestinalis and C. robusta after Bisphenol-A exposure. Values are expressed as mean ± standard error

	Ciona intestinalis			Ciona robusta
	Normal larvae	Malformed larvae	Dead larvae	Normal larvae	Malformed larvae	Dead larvae
Control	91.8 ± 4.5	2.8 ± 2.7	5.5 ± 2.4	81.7 ± 3.8	2.1 ± 1.8	16.2 ± 5.5
DMSO	91.3 ± 5.1	2.3 ± 1.3	6.3 ± 4.0	76.1 ± 5.9	6.5 ± 2.9	17.4 ± 5.7
0.1 µM	90.8 ± 4.2	3.4 ± 4.2	5.8 ± 3.2	72.5 ± 5.2	10.4 ± 3.4	17.1 ± 5.2
0.5 µM	91.8 ± 4.5	2.7 ± 1.4	6.9 ± 4.6	79.7 ± 3.9	8.9 ± 1.5	11.3 ± 2.6
1 µM	91.8 ± 2.1	3.0 ± 2.4	5.1 ± 0.9	75.5 ± 5.0	10.5 ± 2.0	13.9 ± 3.0
5 µM	85.6 ± 7.2	7.7 ± 2.4	6.7 ± 2.4	53.7 ± 10.0	17.4 ± 0.8	28.9 ± 9.9
10 µM	18.9 ± 13.0	57.8 ± 9.2	23.1 ± 10.0	10.9 ± 4.0	47.7 ± 6.1	41.4 ± 9.9
20 µM	0 ± 0	0 ± 0	100 ± 0	0.7 ± 0.6	5.0 ± 3.5	94.3 ± 3.3

DMSO: dimethyl sulfoxide.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.