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[Ilex Coindetii and Todaropsis Eblanae (Cephalopoda, Ommastrephidae): Their Preserit Status in Gaiician Fisheries By

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[Ilex Coindetii and Todaropsis Eblanae (Cephalopoda, Ommastrephidae): Their Preserit Status in Gaiician Fisheries By , .. 1 '" j \ ... , '. International Council for the C.M. 1992/K: 5 Exploration of the Sea Shellfish Commitee . ~ 1 [Ilex coindetii and Todaropsis eblanae (Cephalopoda, Ommastrephidae): their preserit status in GaiiCian Fisheries by Angel F.Gonzalez, Mario Rasero and Angel Guerra Instituto de Investigaciones Mannas (CSIC), Eduardo Cabello 6. 36208 Vigo, Spain Summary • Post-recruit //lex coindetii and Todaropsis eb/anae were collectCd from the fishery on the Galician shelf between November 1991 and April 1992. Sampies were anaiysed separately considering two area~ with different hydrognlphycal characteristics. ~iaturity was assessed using a maturity scale. Growth was determined using length-frequency and modal-progression analysis. I.coinderii males were more precoucious thim females in both areas; the size at first maturity of this species was the same for males in both areas considered, and higher in the north than in the south area for females. T.eb/anae males were more Precoucious than females in both areas;the length at frrst maturity of this species was the same in both areas for males, and higher in ~e nonh than in the south for females. April in both areas was the begining of a spawriing period for I. coinderii . Tbe spawning season ofT. eblariae in the nonh area stans on February, extending at least until April .Sex moos for both species were calculatCd. In I. coiTufeiii four micrOCohons for females and tJrree for males were found in both areas. Growth rate for each micmcohorts was estimated. Two different growth rhythms , one for Spring broods and other for squi'ds born on ea:rly Summer, were observCd~ Femates 'grow fast(~r änd reach larges size than Jrlales. Life Span oftlus S}iecies waS estil11atCd ofone yeu. In T. eblanae only one micmcoholt for each sex and area was fOllOd, except fcr males in thc north area where two micrOCohöns were defuied. GrOwth rates were estirriatCd. Tbe life span of this species was found to bC cf one year. The relationships between D~ and BW of 1. coindetii. and T. eblanae were estimated too. Tbe landing statistics for the Galichin fishery from 1980 to 1991 are presented. .. 2 • Introduction This paper presents the preliminary results of some reeent work on the biology of lI/ex coinderii (Verany,1837) and Todaropsis eb/anae (Ball, 1841) in Galician waters (NW Spain), together with the annuallanding statistics of the Galician fishery from 1980 to 1991. Data are presented on reproduction and growth of both ommastrephid squid species around Galician coast. The present status ofominastrephid squid fishing in Galicia is described. This paper constitutes the first contribution to the knowledge of the life eycle and fishery of lI/ex coindetii in the Atlantie waters of Spain, and the first study ofTodaropsis eb/anae in the Atlantie ocean. \laterials and methods • Sarnples ofl.coinderii and T.eb/anae were obtained from eommerciallandings in two pons of the north ofGalicia (Burela and Celeiro) and one pon of the south of Galicia (Ribeira) (Fig. 1). A total of 3000 l.coinderii and 2425 T.eb/anae in 6 sarnples were examined from ;'!ovember 1991 to April 1992. Sampies were eolleeted from both otter and pair trawlers where squids are taken as by-catch of the hake and blue witting fishery. Squid sarnples were separated in two groups according with the area where they were eaught, the north group comprised all squids colleeted from Ribadeo to Finisterre and the south group was formed by the squids eaught from Finisterre to Miiio river (Fig.l). The distinction of both areas was done.. taking into account the existenee of clear different hydrographie conditions (Fraga et al.,1982), which eould have produced two different stocks. Thc squid colleeted in these sampies were sexed and the total body weight (BW) obtained. Thc dorsal mantle length (DML) was measured to the nearest millimiter. Monthly length e frequeney distributions were analysed using Battaeharya method (1967) employing the software paebge ELEFAN (Gayanilo et al.,1989). This modal-progression analysis provides ~ different population subunits, whieh ean be eonsidered as microcohons (Caddy.199l). Growth rates in length for each of these microcohons were ealeulated. Tbe maturity stage was assessed by a maturity seale of 5 stages for males and 6 stages for females. aeeording to the universal maturity seale (Lipinski.1979). but eonsidering the stages 1 and 2 for males as stage 1. ICES SC r I I 0')< CI) w U Figure 1. Chan of Galicia (NW Spain) showing the main commercial ports of the nonh (Ribadeo-Finisterre) and south one (Finisterre-Mifio River). 3 Results Maruration , . Table 1 shows the percentage ofI.coindetii males and females in each maturiyty stage and DML in the Galician north area. Table 2 shows the same information for the south area. Table 1. Percentage (%) of I. coindetii males and females in each maturity stage and DML classes in nonh area. Males Females ~ laturity stage 1 2 3 4 5 1 2 3 4 5 6 DML(mm) 60-79 100 • 80-99 100 100 100-119 92.8 6.0 0.6 0.6 100 120-139 48.5 27.8 19.7 4.0 93.3 6.7 1~0-159 3.8 22.3 29.9 44.0 69.1 27.3 1.8 1.8 160-179 0.7 2.8 9.2 87.3 27.0 47.67.9 6.4 11.1 180-199 2.7 2.7 94.6 3.7 53.7 13.4 6.1 23.1 200-219 100 35.6 28.8 13.6 22.0 220-239 5.6 94.4 9.1 38.6 13.7 38.6 240-259 100 11.8 11.8 17.6 52.9 5.9 260-279 100 22.2 22.2 44.4 11.2 280-299 22.2 11.1 55.6 11.1 300-319 16.7 16.7 49.9 16.7 320-339 20.0 60.0 20.0 340-359 60.0 20.0 20.0 360-379 50.0 50.0 I.coindetii males are more precoucious than females in both areas. The smallest mature male measured 119 mm DML in the nonh area and 93 mm in the south one, while the smallest mature fern ales were of 148 and 160 mm DML respectively. The size of the mature males ranged from 119-263 mm DML in the nonh , and from 93-230 mm DML in the south, while the size ofthe mature females ranged from 148-345 mm DML in the nonh area, and from 160­ 325 mm DML in the south one. Spent males were not found, and very few spent females were caught in the sampies. 4 Tbe size at first maturity ( DML at which 50% of the specimens were mature in the population) was the same (160-179 mm) for males in both areas considered, and higher in the ,.I' north (220-239 mm) than in the south (200-219 mm) for females. Table 2. Percentage (%) ofI. coindetii males and females in each maturity stage and DML classes in south area. Males Females Maturity stage 1 2 3 4 5 1 2 3 4 5 6 DML(mm) 60-79 100 100 80-99 98 0.7 1.3 100 100-119 76.0 14.8 3.7 5.5 96.6 3.1 120-139 35.9 29.6 19.5 15.0 92.5 5.7 1.2 0.6 • 140-159 6.3 13.0 33.2 47.5 71.4 24.3 0.7 3.6 160-179 3.3 13.0 83.7 14.8 69.4 9.3 5.6 0.9 180-199 100 5.3 66.7 17.5 5.3 3.5 1.7 200-219 25.0 75.0 14.3 28.6 22.8 34.3 220-239 100 15.2 9.1 30.3 45.4 240-259 21.4 28.6 50.0 260-279 50.0 50.0 280-299 25.0 75.0 300-319 100 320-339 100 , Table 3 shows the percentage ofT.eb/anae males and females in each maturity stage and DML in north area. Table 4 shows the same information for south area. T.eb/anae males are more precoucious than fernales in both areas. Tbe smallest mature male measured 104 mm DML in the north and 98 mrn DML in the south , while the smallest fern ales were af 140 mrn and 141 mrn DML respectively. The size ofthe mature males ranged from 104-169 mm DML in the north area, and from 98-149 in the south, while the size of the mature females ranged from 140-219 mm DML in the north , and from 141-219 mm DML in the south. Spent males (stage 5) were found in both areas,while very few spent females were caught in the sarnples. The size at fIrst maturity was the same (130-149 mm DML) in both areas for males, and higher (180-199 mm) in the nanh than in the south (160-179 mm) far females. 5 Table 3. Percentage(%) of T.eblanae males and females in each maturity stage and DML classes in nonh area. Males Females Maturity stage 1 2 3 4 5 1 234 5 6 DML(mm) DML 50-69 100 40-59 100 70-89 95.2 4.8 60-79 100 90-109 50.0 46.0 3.6 0.4 80-99 97.6 1.7 0.7 110-129 3.5 61.0 22.7 12.0 0.8 100-119 78.7 20.7 0.6 130-149 4.8 25.3 65.0 4.9 120-139 41.5 48.8 9.7 150-169 15.8 73.7 11.5 140-159 4.2 45.8 45.8 4.2 • 160-179 6.6 13.4 40.0 20.0 20.0 180-199 12.5 18.8 68.7 200-219 10.0 10.0 80.0 Table 4.
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