New Data on the Systematics of Comb-fin Squids Chtenopteryx spp. (Cephalopoda: Chtenopterygidae) from the Canary Islands Author Escánez, Alejandro BioCephaLab, Departamento de Ecoloxía e Bioloxía Animal, Edificio de Ciencias Experimentais, Campus As Lagoas-Marcosende, Universidade de Vigo, 36310 Vigo, Spain & Departamento de Biología Animal, Facultad de Biología, Avenida Astrofísico F. Sánchez, s / n, 38206, Universidad de la Laguna, Tenerife, Spain. E-mail: aescanez @ msn. com aescanez@msn.com Author Roura, Álvaro ECOBIOMAR, Instituto de Investigaciones Marinas (IIM-CSIC). Eduardo Cabello 6, 36208 Vigo, Spain. Author Riera, Rodrigo Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile. E-mail: rriera @ ucsc. cl & Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile rriera@ucsc.cl Author González, Ángel Francisco ECOBIOMAR, Instituto de Investigaciones Marinas (IIM-CSIC). Eduardo Cabello 6, 36208 Vigo, Spain. Author Guerra, Ángel ECOBIOMAR, Instituto de Investigaciones Marinas (IIM-CSIC). Eduardo Cabello 6, 36208 Vigo, Spain. text Zoological Studies 2018 2018-12-30 57 40 1 11 journal article 10.6620/ZS.2018.57-40 1810-522X PMC6409442 31966280 13316236 Chtenopteryx sicula ( Vérany, 1851 ) ( Figs. 2B, 2D , 4 ) Synonyms: Calliteuthis neuroptera Jatta, 1896 ; Chtenopteryx fimbriatus Appellöf, 1890 ; Ctenopteryx cyprinoides Joubin, 1894 . Material examined : Fifty-one specimens of C. sicula were captured around El Hierro, La Palma and Tenerife ( Spain , NE Atlantic Ocean) (see Table 1 and 3 for details). Description : The diagnostic characters of the specimens caught in the Canary Islands agree with those described by Guerra (1992) . A dorsal light organ is present in the posterior part of the mantle in mature males ( Fig. 3B ). The studied specimens have a clear visceral photophore on the ink sac dorsal to the intestine in immature and mature males and females ( Fig. 2D ). Buccal membrane with two series of suckers. Suckers on arms I-II and III have the suckers in two transversal series along the arms and four series distally ( Fig. 4A, B ), while sucker on arms IV are positioned in two zigzag transversal series ( Fig. 3C ), whilst the tentacular clubs present 8-14 series of suckers. Table 3. Biometric data of Chtenopteryx spp. caught in the Canary Islands. Reference number (RN); dorsal mantle length (ML, mm); mantle width (MW, mm), weight in grams (W); Sex (S): In: indeterminate; M: male, F: female; Maturity stage (MI): I: immature, II: maturating, III: mature; -: no data; D: damaged

Species	RN	ML	MW	W	S	MI	Species	RF	ML	MW	W	S	MI
C. sicula	EH1-1	21	-	0.92	-	-	C. sicula	EH1-32	24	13	1.24	In	-
C. sicula	EH1-10	29	17	1.70	M	III	C. sicula	EH1-33	20	-	0.83	In	-
C. sicula	EH1-11	27	17	1.18	M	II	C. sicula	EH1-34	26	13	1.13	M	II
C. sicula	EH1-12	27	15	1.28	M	II	C. sicula	EH1-35	27	-	-	-	D
C. sicula	EH1-13	29	19	1.39	M	III	C. sicula	EH1-36	18	-	-	-	D
C. sicula	EH1-14	24	15	1.25	In	-	C. sicula	EH1-4	-	-	0.26	In	-
C. sicula	EH1-15	28	14	1.97	F	II	C. sicula	EH1-5	-	-	0.62	In	-
C. sicula	EH1-16	30	-	2.25	M	II	C. sicula	EH1-6	-	-	0.51	In	-
C. sicula	EH1-17	19	-	0.86	In	-	C. sicula	EH1-7	23	14	0.87	M	II
C. sicula	EH1-18	34	-	3.51	F	III	C. sicula	EH1-8	24	16	1.30	M	II
C. sicula	EH1-19	24	-	1.01	M	I	C. sicula	EH1-9	27	17	1.40	M	II
C. sicula	EH1-2	20	-	0.61	In	-	C. sicula	EH8-1	20	-	1.14	In	-
C. sicula	EH1-20	25	13	1.24	In	-	C. sicula	EH8-2	19	-	0.76	In	-
C. sicula	EH1-21	22	-	0.95	In	-	C. sicula	EH8-3	-	-	0.68	In	-
C. sicula	EH1-22	22	11	0.99	In	-	C. sicula	LP12-1	33	-	1.80	F	I
C. sicula	EH1-23	25	-	1.27	In	-	C. sicula	TF2-1	25	-	1.32	In	-
C. sicula	EH1-24	30	14	1.95	F	D	C. sicula	TF2-2	27	-	1.73	In	-
C. sicula	EH1-25	24	-	1.26	M	II	C. sicula	TF2-3	23	-	1.03	In	-
C. sicula	EH1-26	24	-	0.92	In	-	C. sicula	TF2-4	-	-	0.20	In	-
C. sicula	EH1-27	24	10	1.14	In	-	C. sicula	TF4-1	25	-	0.84	M	I
C. sicula	EH1-28	23	-	1.03	In	-	C. sicula	TF5-1	33	-	3.00	F	III
C. sicula	EH1-29	22	-	0.99	F	I	C. sicula	TF6-1	30	-	2.10	In	-
C. sicula	EH1-3	19	-	0.55	In	-	C. sicula	TF6-2	26	-	1.37	In	-
C. sicula	EH1-30	21	-	0.76	In	-	C. sicula	TF6-3	23	-	1.29	In	-
C. sicula	EH1-31	23	-	1.29	M	II	C. sicula	TF6-4	29	-	1.85	In	-
C. canariensis	TF-9	43	19	13.80	F	III	C. canariensis	OC-1	32	13	2.80	M	III
C. canariensis	TF-1	27	-	2.40	In	-

© 2018 Academia Sinica, Taiwan Genetic analysis Of the 582 bp aligned for COI sequences, 95 were variable and 78 were parsimony-informative sites. Mean nucleotide composition was 29.8% (A), 35.6% (T), 19.8% (C) and 14.8% (G). The twelve partial COI sequences of Chtenopteryx species analysed in this study clustered in four distinct groups in the MaxL phylogenetic tree ( Fig. 5 ). A well supported group with bootstrap values of 99 (BP = 99) was identified as C. sicula (Atlantic Ocean). A second group was identified as C. sicula (Pacific Ocean) (BP = 100). A third clade was identified as C. canariensis group (BP = 99), and finally a clade formed by a unique sequence was identified as Chtenopteryx sp. (West Pacific) ( Fig. 5 ). The partial COI sequence obtained for C. canariensis was clustered with two COI sequences classified as C. sicula (EU735369: caught in the Bear Seamount, NW Atlantic) and Chtenopteryx sp. (EU735388: collected north of the Azores archipelago, eastern Atlantic). The specimens belonging to this clade shared the same haplotype and therefore intragroup genetic divergence was TN = 0. The three C. sicula partial COI sequences obtained in this study grouped together with a C. sicula (GU145076) collected in the SW Atlantic Ocean. The intragroup genetic distance for this clade was TN = 0.004 ± 0.002. Finally, the clade formed by the GenBank sequences HQ386019; HQ386018; AY557526; AY293705, classified as C. sicula and collected from the Pacific Ocean, showed an intragroup genetic distance of TN = 0.001 ± 0.001. Fig. 2. (A) Chtenopteryx canariensis , 43 mm ML female specimen captured in Canary Islands, ventral view. (B) Chtenopteryx sicula , 34 mm ML mature female captured in Canary Islands. (C) Ink sack of C. canariensis without visceral photophore. (D) Visceral photophore on ink sack of C. sicula . © 2018 Academia Sinica, Taiwan The pairwise intergroup genetic distances between the four clusters formed in the MaxL phylogenetic tree ranged from 9.8% to 12.4% ( Table 4 ). The more divergent clades corresponded to those including C. sicula and C. canariensis , while the lowest divergence was obtained between C. sicula from the Pacific Ocean and C. canariensis .