Osteometry and size reconstruction of the Indian and Pacific Oceans' Euthynnus species, E. affinis and E. lineatus (Scombridae)

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Pacific Oceans’ Euthynnus species, E. aﬀinis and E.

lineatus (Scombridae)

Anais Marrast, Philippe Béarez

To cite this version:

Anais Marrast, Philippe Béarez. Osteometry and size reconstruction of the Indian and Pa- cific Oceans’ Euthynnus species, E. aﬀinis and E. lineatus (Scombridae). Cybium : Revue In- ternationale d’Ichtyologie, Paris : Muséum national d’histoire naturelle, 2019, 43, pp.187 - 198.

�10.26028/cybium/2019-423-007�. �hal-02401150�

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Osteometry and size reconstruction of the Indian and Pacific Oceans’

Euthynnus species, E. affinis and E. lineatus (Scombridae)

by

Anaïs MArrAst* (1) & Philippe BéArez (1)

(1) Archéozoologie, archéobotanique: sociétés, pratiques et environnements (AAsPe), Muséum national d’histoire naturelle, CNrs, CP 56, 57 rue Cuvier, 75005 Paris, France. [[email protected]] [[email protected]]

* Corresponding author [[email protected]]

Found worldwide in tropical to temperate waters, the scombrid genus Euthynnus is represented by three different species: E. alletteratus (Rafinesque, 1810), the little tunny;

E. lineatus (Kishinouye, 1920), the black skipjack; and E. affinis (Cantor, 1849), the kawakawa or mackerel tuna.

the first is present in the tropical Atlantic and the Medi- terranean, while the other two are present in the tropical Eastern Pacific and the Indo-Pacific, respectively. Euthyn- nus species are epipelagic, essentially neritic fishes, which occur in open waters but generally stay inshore. they have a robust, elongated and streamlined body, and are known to form large multi-species schools with other scombrids or even other taxa. these schools reach between 100 and 5000 individuals (Collette and Nauen, 1983).

All three species are currently commercially important for both industrial and small-scale fisheries, but they

also played an important role in ancient subsistence fisheries. evidence that these neritic species were consumed by coastal populations is attested by their presence on many archaeological sites around the world, such as in the eastern Pacific (Béarez, 1996; Martínez et al., 2009; Béarez et al., 2012), the Western Atlantic (Wing, 2001), the Mediterra- nean (Desse and Desse-Berset, 1994) and the Northern Indi- an Ocean (Beech, 2004; Uerpmann and Uerpmann, 2003).

Apparently, Euthynnus affinis is less common in the Central Pacific archaeological record, where it seems to be replaced by the closely related skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) (Lambrides and Weisler, 2017).

Despite the fact that Euthynnus species, especially E. affinis, have commercial importance, only a few papers provide information on their osteology or osteometry (Kishi- nouye, 1923; Godsil, 1954; Mansueti and Mansueti, 1962), Abstract. – two neritic species of scombrids (Euthynnus affinis and E. lineatus) from the Indo-Pacific and the Eastern Pacific are today classed as commercially important. They have long been exploited and are common finds on coastal archaeological sites. size reconstruction from isolated bones is interesting for both biologists and archaeologists. In archaeology, these studies make it possible to highlight fishing strategies. Therefore, we built an osteometric model for these two species, using 31 specimens of E. affinis (FL: 274 mm to 828 mm, W: 305 g to 8674 g) from the sultanate of Oman and 26 specimens of E. lineatus (FL: 294 mm to 614 mm, W: 481 g to 4200 g) from ecuador. For E. affinis, the length-weight relationship is W = 1e-05 FL^3.0682, and for E. lineatus, the relationship is W = 2e-05 FL^2.9578, with r² higher than 0.98 for both species. For the osteometric model, we used the neurocranium, premaxilla, dentary, anguloarticular, quadrate, hyomandibula, maxilla, opercle, anterior and posterior ceratohyals, scapula and vertebrae. For each bone, we took between 2 and 5 measurements and plotted the obtained values against the fork length. For all selected bones, we produce at least one regression equation with a high r² (> 0.9) that permits accurate estimates of the length and weight of Euthynnus individuals for both species.

Résumé. – Ostéométrie et reconstruction de la taille des espèces du genre Euthynnus des océans Indien et Pacifi- que, E. affinis et E. lineatus (scombridae).

Deux espèces néritiques de scombridés (Euthynnus affinis et E. lineatus) de l’Indo-Pacifique et du Pacifique est sont aujourd’hui considérées comme commercialement importantes. elles sont exploitées depuis longtemps et sont souvent identifiées sur les sites archéologiques côtiers de cette partie du monde. La reconstitution de la taille d’un poisson à partir d’os isolés est d’un grand intérêt pour les biologistes et les archéologues. en archéo- logie, ces études permettent notamment de renseigner les stratégies de pêches. Nous avons donc construit un modèle ostéométrique pour ces deux espèces, en utilisant 31 spécimens d’E. affinis (FL : 274 mm à 828 mm, W : 305 g à 8674 g) du sultanat d’Oman et 26 spécimens d’E. lineatus (FL : 294 mm à 614 mm, W : 481 g à 4200 g) d’équateur. Pour E. affinis, la relation longueur-poids est W = 1e-05 FL^3,0682, et pour E. lineatus, la relation est W = 2e-05 FL^2,9578, avec un r² supérieur à 0,98 pour les deux espèces. Pour le modèle ostéométrique, nous avons utilisé le neurocrâne, le prémaxillaire, le dentaire, l’anguloarticulaire, le carré, l’hyomandibulaire, le maxillaire, l’operculaire, les ceratohyaux antérieur et postérieur, la scapula et des vertèbres. Pour chaque os, nous avons pris entre 2 et 5 mesures et représenté les valeurs par rapport à la longueur à la fourche. Pour tous les os sélectionnés il y a au moins une équation de régression avec un r² élevé (> 0,9) qui permet des estimations précises de la longueur et du poids des individus des deux espèces Euthynnus.

Submitted: 19 Oct. 2018 Accepted: 21 Feb. 2019 Editor: E. Dufour

Key words Euthynnus Osteometry size reconstruction Allometry Length-weight

relationship Ichthyoarchaeology

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while more information on their growth is available (e.g.

Landau, 1965; Mulhia-Melo, 1980; Valeiras et al., 2008).

In fish, body shape, as well as body parts or organs, most

often scale allometrically with total length. the reconstruction of fish lengths from isolated bones is significant for both biology and archaeology (reitz et al., 1987). In biology, it Table I. – Description of the measurements illustrated in figure 2.

Anatomical element Measurement

number Measurement description

Neurocranium / ncr ncr 1 Distance from the anterior part of the vomer to the posterior part of the basioccipital ncr 2 Maximal width of the vomer

ncr 3 Maximal width between sphenotics

Premaxilla / pmx

pmx 1 Length of the anterior dorsal process (without teeth)

pmx 2 Distance from the anterior tip of the pmx to the posterior base of the dorsal process (without teeth)

pmx 3 Medio-lateral width at posterior level of the dorsal process Dentary / dn dn 1 Length of the dorsal dentigerous branch

dn 2 Height of the symphysis

dn 3 Distance from the symphysis to the postero-lateral incisure

Anguloarticular / ang

ang 1 total length

ang 2 Distance from the dorsal curvature to the posterior part of the articular process ang 3 Medio-lateral width of the articular facet

ang 4 total height of the articular Quadrate / qd qd 1 total width of the articular condyle

qd 2 Distance from the articular condyle to the tip of the preopercular process Hyomandibula / hm hm 1 total height

hm 2 Greatest medio-lateral width at level of the opercular process

hm 3 Greatest distance between the sphenotic facet and the opercular process

Maxilla / mx mx 1 total length

mx 2 Height of the main axis

mx 3 Greatest width of the anterior portion Opercle / op op 1 Cranio-caudal length of the articular fossa

op 2 Greatest height

op 3 Height of the articular fossa Anterior ceratohyal / ach ach 1 Greatest cranio-caudal length

ach 2 Height of the external median bridge Posterior ceratohyal / pch pch 1 Greatest cranio-caudal length

pch 2 Greatest dorso-ventral height

scapula / sca sca 1 Distance between the scapular foramen and the articular facet sca 2 Medio-lateral width of the articular facet

First vertebra/ pc 1

M1 Anterior height of the centrum, including the neural prezygapophyses M2 Greatest width at level of neural prezygapophyses

M3 Length of the centrum M4 Posterior height of the centrum M5 Posterior width of the centrum

Vertebrae

M1 Anterior height of the centrum M2 Anterior width of the centrum M3 Length of the centrum M4 Posterior height of the centrum M5 Posterior width of the centrum Hypural plate / hp M1 Height of the ural centrum

M2 Width of the ural centrum M3 Height of the triangular plate

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allows the estimation of prey size in the diet of predators (e.g.

tunas, billfishes, sharks). In archaeology, length reconstructions are important for the study of ancient fisheries since they allow the estimation of the fish biomass represented in the site: human population consumption, information about the fish sizes targeted (juveniles/adults) and fishing gear design (e.g. mesh size of fishing nets, size of fish hooks). Size reconstruction also allows the perception of changes in fish catches through time, and inferences about the evolution of fishing techniques or the status of the exploitation of the species to be made (reitz et al., 1987; Thieren and Van Neer, 2016;

Prestes-Carneiro and Béarez, 2017; Lidour et al., 2018).

the study of the relationships between body part lengths or between length and body weight is of particular value in fishery management (Ricker, 1958), ecological studies (Kul- bicki et al., 2005) or body size reconstruction from isolated parts (Casteel, 1974; Lidour et al., 2018).

In this study, we present the relationship between selected fish bone measurements and fish length for Euthynnus

affinis and E. lineatus. We focused on these two species from the Indian and Pacific Oceans, because of their importance in this area both for modern and ancient fisheries (e.g. Béa- rez and Lunniss, 2003; Rohit et al., 2012); the third commercially important species is excluded because information on osteometry in E. alletteratus is already available (Desse and Desse-Berset, 1994).

Euthynnus affinis is found throughout the Indo-Pacific Ocean, from East Africa, the Red Sea and the Persian Gulf to Hawaii, Polynesia. Its maximum fork length is 100 cm, with a maximum weight of 13.6 kg, but the average length is about 60 cm (Collette and Nauen, 1983). Unlike other tunas, which can resist temperatures down to 10°C, it is always found in warm waters, between 18° to 29°C (Brill, 1994). In the Arabian Sea, the species reaches between 50 and 65 cm in its third year of age, and spawning is observed all year round with peaks during June and October (rohit et al., 2012). Euthynnus lineatus lives in the Eastern Pacific, along the coast of Western America, from California to Peru.

species Number in collection tL FL sL W Euthynnus affinis MNHN-ICOS-01132 889 828 790 8674 Euthynnus affinis MNHN-ICOS-01131 842 806 772 8091 Euthynnus affinis MNHN-ICOS-01130 795 721 685 6420 Euthynnus affinis MNHN-ICOS-00320 776 725 682 6600 Euthynnus affinis MNHN-ICOS-00239 765 714 690 5950 Euthynnus affinis MNHN-ICOS-00319 722 679 654 4900 Euthynnus affinis MNHN-ICOS-1433 690 592 630 4330 Euthynnus affinis MNHN-ICOS-00295 678 631 605 4050 Euthynnus affinis MNHN-ICOS-00273 671 622 600 4030 Euthynnus affinis MNHN-ICOS-00238 660 611 590 3600 Euthynnus affinis MNHN-ICOS-00296 640 587 567 3150 Euthynnus affinis MNHN-ICOS-00297 636 588 565 3000 Euthynnus affinis MNHN-ICOS-00298 626 575 553 2850 Euthynnus affinis MNHN-ICOS-00272 616 552 552 2788 Euthynnus affinis MNHN-ICOS-00994 610 539 521 2670 Euthynnus affinis MNHN-ICOS-00299 609 560 539 2950 Euthynnus affinis MNHN-ICOS-00271 584 543 530 2446 Euthynnus affinis MNHN-ICOS-00300 578 525 507 2500 Euthynnus affinis MNHN-ICOS-00986 570 510 489 2102 Euthynnus affinis MNHN-ICOS-00107 564 519 499 2000 Euthynnus affinis MNHN-ICOS-00301 536 497 481 1940 Euthynnus affinis MNHN-ICOS-00311 531 497 477 1983 Euthynnus affinis MNHN-ICOS-01103 513 486 472 1797 Euthynnus affinis MNHN-ICOS-00985 495 423 406 1334 Euthynnus affinis MNHN-ICOS-00312 492 455 438 1484 Euthynnus affinis MNHN-ICOS-00249 467 431 414 1151 Euthynnus affinis MNHN-ICOS-00960 425 383 368 998 Euthynnus affinis MNHN-ICOS-00956 398 359 349 694 Euthynnus affinis MNHN-ICOS-00955 393 353 342 703

species Number in collection tL FL sL W Euthynnus affinis MNHN-ICOS-00984 319 288 275 343 Euthynnus affinis MNHN-ICOS-00983 308 274 263 305 Euthynnus lineatus MNHN-ICOS-01608 666 614 578 4200

Euthynnus lineatus – 619 565 530 3250

Euthynnus lineatus MNHN-ICOS-01630 580 525 490 2517 Euthynnus lineatus MNHN-ICOS-01609 565 525 493 2500 Euthynnus lineatus MNHN-ICOS-01629 510 466 440 1723

Euthynnus lineatus MNHN-ICOS-01618 506 455 430 1457

Euthynnus lineatus MNHN-ICOS-01612 495 435 412 1394 Euthynnus lineatus MNHN-ICOS-01625 495 444 420 1450 Euthynnus lineatus MNHN-ICOS-01627 470 423 400 1335 Euthynnus lineatus MNHN-ICOS-01624 450 396 375 1129 Euthynnus lineatus MNHN-ICOS-01626 445 407 385 1143 Euthynnus lineatus MNHN-ICOS-01628 430 385 365 1005 Euthynnus lineatus MNHN-ICOS-01620 425 380 360 944 Euthynnus lineatus MNHN-ICOS-01621 418 380 360 886 Euthynnus lineatus MNHN-ICOS-01611 413 374 355 883 Euthynnus lineatus MNHN-ICOS-01623 412 364 345 828 Euthynnus lineatus MNHN-ICOS-01622 401 359 340 727 Euthynnus lineatus MNHN-ICOS-01619 390 348 330 750 Euthynnus lineatus MNHN-ICOS-01613 360 326 310 646 Euthynnus lineatus MNHN-ICOS-01614 350 316 300 550 Euthynnus lineatus MNHN-ICOS-01610 346 311 295 481 Euthynnus lineatus MNHN-ICOS-01615 340 316 300 558 Euthynnus lineatus MNHN-ICOS-01617 330 294 280 535 Euthynnus lineatus MNHN-ICOS-01616 320 294 280 524 Table II. – Biometric information concerning Euthynnus affinis and Euthynnus lineatus specimens (TL, FL and SL in mm; P in g).

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Its maximum fork length is 84 cm, with a maximum weight of 9 kg, but the average length is about 60 cm (Collette and Nauen, 1983). Along the coast of Central America, spawning season occurs from October to June (schaefer, 1987).

MAteRiAl And MethodS

For this study, we analysed 31 specimens of Euthynnus affinis from the Gulf of Oman and 26 specimens of E. linea-linea- Figure 1. – General view of Euthynnus

affinis (A) and Euthynnus lineatus (B) and some selected vertebrae: eight first precaudals (lateral vieuw) and nine first preurals (lateral and dorsal views).

tus from Ecuador, Tropical Eastern Pacific. In order to attain the most representative samples, and to avoid the need for extrapolation, specimens were collected from within the widest size range possible. For all specimens, the total length (tL), fork length (FL), and standard length (sL) were recorded to the nearest millimetre (mm), and the total fresh weight (W) was recorded to the nearest gram (g) (Tab. I).

their complete skeletons were prepared in the Muséum national d’Histoire naturelle in Paris, where they are now stored (Tab. II).

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Figure 2. – Description of the measurements used (see Tab. I).

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In order to obtain reliable size reconstructions, our osteometric model was based on the allometric principle, which gives the best predictive model (Teissier, 1948; Cas- teel, 1974; Reitz et al., 1987). Indeed, allometry takes into account the fact that different parts of the body may have distinct growth rates, which is a common feature in fish. The length-weight relationship is represented by a power function of the type: W = aFL^b (Teissier, 1948; Le Cren, 1951), where W is the total weight of the fish (g), FL is the fork length (mm), “a” is a constant and “b” is the allometric coefficient.

the length-length relationships are expressed as FL = aBM^b, where BM is the bone measurement. the accuracy of the equations was evaluated by the coefficient of determination (r²) and the standard error of estimate (see).

Among archaeological material, depending on preservation, bones can be severely fragmented, with only their strongest parts, mostly articular joints, surviving. For this reason, some bone measurements were taken on parts selected for their good preservation, and several flat bones (e.g.

preopercle, subopercle, interopercle), which do not preserve well, were not considered in this study. According to our archaeological observations and research on the bones mostly used in biometric studies (Desse, 1984), we decided to focus our study on the bones more easily assigned to species:

premaxilla, dentary, maxilla, opercle, quadrate, anguloarticular, ceratohyal, hyomandibula and neurocranium (Fig. 1).

We then added the scapula because this bone is often well preserved among scombrids in an archaeological context.

Figure 3. – Length-length and length-weight relationships for Euthynnus affinis (left) and Euthynnus lineatus (right).

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For each cranial bone, we took between 2 and 4 measurements (Tab. I, Fig. 2), based on previous works by Morales and rosenlund (1979) and Desse (1984). All the measurements were taken with a digital caliper (0.01 mm). Osteolog- ical nomenclature followed Dye and Longenecker (2004).

For the vertebrae, the problem of identifying their posi- tion along the spinal column was overcome by using the Global Rachidian Profile (GRP) (Desse et al., 1989). since the last precaudal and first caudal vertebrae are very similar, GRP allows one to select parts of the spinal column where the vertebral diameter does not vary much, which means that any vertebra in the segment could give the same size reconstruction. The GRP can also be used to estimate the Minimum Number of Individuals (MNI) of Euthynnus in fish bones assemblages. In order to construct this profile, we took 5 measurements on each vertebra from modern specimens, for which all the vertebrae were conserved with their original rank.

Otoliths were not studied, as they are very small and are generally not recovered, either in archaeological material or stomach contents.

All the measurements were plotted against the FL of individuals (in mm). We chose FL instead of tL because Euthynnus species have a strong lunate tail that makes meas- uring the total length difficult, and because FL is the most frequently used length in tuna-like fisheries.

ReSultS

the specimens of Euthynnus affinis have a FL ranging from 274 mm to 828 mm, and a weight ranging from 305 g to 8674 g (Tab. II; Fig. 3). The specimens of Euthynnus lineatus have a FL ranging from 294 mm to 614 mm, and a weight ranging from 481 g to 4200 g (Tab. II; Fig. 3).

the two species are allopatric except for a few stray specimens, and hence should not be confused. However, they can also be separated by the spots and lines on their body or sorted by differences in their vertebrae; Euthynnus lineatus always has a marked hyperostosis in its 5^th and 6^th preural vertebrae (Béarez et al., 2005). Both Euthynnus species can be differentiated from the closely related Katsuwonus pela- mis thanks to the presence of lines on the abdomen, and oste- ologically on the basis of their vertebrae. Katsuwonus pela- mis has precaudal vertebrae with thinner and more elongate holes over the median ridge on the lateral parts of the centra than Euthynnus species.

the relationships between lengths or between length and weight given by the power regression equations are highly significant for both species. Most determination coefficients (r²) are over 0.9, scoring slightly higher in Euthynnus affinis.

These significant correlations between the skeleton parts and the size and weight of individuals allow reliable reconstructions of life size. some measurements are, however, less significant; for E. affinis, this is the case for the M2 of the DN (0.83), and the M3 of the PU1 (0.81); and for E. lineatus, the

Figure 4. – Global rachidian profiles of Euthynnus affinis (MNHN-ICOS-00983: SL = 263 mm, FL = 274 mm, W = 305 g; MNHN- ICOS-00986: SL = 489 mm, FL = 510 mm, W = 2102 g; MNHN-ICOS-1130: SL = 685 mm, FL = 721 mm, W = 6420 g) and Euthynnus lineatus (dotted line, PB-6664: sL = 493 mm, FL = 525 mm, W = 2500 g).

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BoneMeasurementequationr2see ncrncr 1y = 5.2615x1.10570.990516.2846 ncr 2y = 48.424x0.92480.989616.8776 ncr 3y = 9.0822x1.02760.987318.8479 pmxpmx 1y = 36.07x0.94890.975423.5420 pmx 2y = 37.19x1.00950.959029.4210 pmx 3y = 196.25x0.96220.880447.3650 dndn 1y = 5.8451x1.17680.982421.7980 dn 2y = 95.52x0.83780.96530.1513 dn 3y = 16.744x1.07380.975122.5286 ang

ang 1y = 5.4654x1.15710.985518.2458 ang 2y = 22.201x1.06320.987517.4743 ang 3y = 145.12x0.84510.955136.0657 ang 4y = 34.909x0.96190.978924.2272 qdqd 1y = 152.57x0.82090.918346.2016 qd 2y = 21.565x0.99420.991913.1806 hmhm 1y = 10.867x1.03220.990616.1084 hm 2y = 33.302x0.95560.977224.0559 hm 3y = 67.172x0.95610.948936.5657 mxmx 1y = 8.5473x1.0950.987815.9913 mx 2y = 139.72x0.87330.852653.9242 mx 3y = 80.859x1.02760.980719.0873 opop 1y = 45.382x1.01170.963531.0683 op 2y = 45.382x1.01170.9635129.4188 op 3y = 45.382x1.01170.9635127.8943 achach 1y = 11.192x1.09030.988816.0867 ach 2y = 118.95x0.93480.938841.8872 pchpch 1y = 29.724x1.0150.981420.7912 pch 2y = 41.277x0.90540.972027.8825 scasca 1y = 163.54x0.80130.944241.4283 sca 2y = 120.51x0.88950.826164.5534 pc 1

M1y = 61.202x0.87270.975621.5510 M2y = 48.714x1.02390.935138.3012 M3y = 122.94x0.75890.963830.9592 M4y = 86.297x0.830.988516.7135 M5y = 95.078x0.81410.95435.2393 pc 2 M1y = 90.397x0.81270.976921.7212 M2y = 94.487x0.80630.950834.6229 M3y = 85.87x0.85660.971226.7243 M4y = 88.639x0.85750.975223.2340 M5y = 83.534x0.82870.974928.3761

BoneMeasurementequationr2see pc 3

M1y = 93.054x0.83610.978223.3623 M2y = 91.977x0.79350.963431.3574 M3y = 81.568x0.89040.977624.6110 M4y = 95.817x0.85610.982120.2419 M5y = 87.8x0.78670.978126.8131 pc 4

M1y = 87.091x0.89360.974232.2053 M2y = 86.755x0.8270.987330.6535 M3y = 70.606x0.93970.985926.6567 M4y = 78.462x0.93480.980333.4870 M5y = 91.675x0.79320.982634.8516 pu 8

M1y = 72.634x0.86160.942936.2072 M2y = 79.641x0.79010.975227.1680 M3y = 72.345x0.75770.948333.8715 M4y = 68.2x0.86540.954730.0470 M5y = 77.557x0.77170.983220.3948 pu 7 M1y = 76.065x0.82810.981224.1060 M2y = 75.238x0.78490.983321.2338 M3y = 73.197x0.70820.94835.7684 M4y = 62.63x0.90410.943730.6240 M5y = 82.699x0.73030.985320.3260

BoneMeasurementequationr2see pu 6

M1y = 100.06x0.92660.962426.8710 M2y = 113.02x0.89690.871261.6445 M3y = 188.3x0.76710.741380.4127 M4y = 125x0.76460.918524.8901 M5y = 95.695x0.94570.965527.4408 pu 1

M1y = 105.41x0.89410.984122.8050 M2y = 117x0.96980.907644.9523 M3y = 204.59x0.89110.813660.6825 M4y = 162.45x0.65030.861833.4825 M5y = 104.8x0.94350.937841.6108 hpM1y = 120.61x0.87130.985718.6626 M2y = 129.02x1.01210.941833.2386 M3y = 36.528x0.88660.992910.8054

Table III. – Allometric relationships between fork length and bone measurements for Euthynnus affinis (FL = aBMb). Number of specimens: 30.

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Table IV. – Allometric relationships between fork length and bone measurements for Euthynnus lineatus (FL = aBMb). Number of specimens: 21-22. BoneMeasurementequationr2see ncrncr 1y = 6.4785x1.0382 0.98309.8153 ncr 2y = 52.438x0.89810.981811.6257 ncr 3y = 16.363x0.85840.920828.4773 pmxpmx 1y = 34.318x0.93660.961714.3914 pmx 2y = 37.78x0.97650.962514.4471 pmx 3y = 196.67x0.87370.795835.1222 dndn 1y = 7.8663x1.07570.965812.9910 dn 2y = 98.44x0.79890.938118.1801 dn 3y = 27.315x0.88740.926319.3894 ang

ang 1y = 6.9066x1.07770.98289.5603 ang 2y = 22.924x1.03590.974812.0622 ang 3y = 144.44x0.79590.962316.2330 ang 4y = 32.717x0.96780.961714.9794 qdqd 1y = 136.55x0.87030.934219.1446 qd 2y = 24.759x0.9310.967312.9685 hmhm 1y = 12.386x0.97670.980510.5917 hm 2y = 34.503x0.92410.973813.3588 hm 3y = 71.948x0.88230.927520.5952 mxmx 1y = 8.7044x1.070.98179.9004 mx 2y = 136.68x0.82720.742039.0486 mx 3y = 91.704x0.94450.911123.9390 opop 1y = 52.815x0.9210.932619.2882 op 2y = 12.756x0.91080.978112.0354 op 3y = 108.09x0.85380.947917.8224 achach 1y = 12.953x1.02860.979211.3792 ach 2y = 156.93x0.70960.817530.4365 pchpch 1y = 29.943x0.99320.978811.1191 pch 2y = 44.995x0.85510.938918.9375 scasca 1y = 147.72x0.83220.937620.8655 sca 2y = 139.65x0.80060.936519.3598 pc 1

M1y = 62.112x0.84190.98259.5511 M2y = 52.691x0.95360.969677.6146 M3y = 105.42x0.78530.905426.1891 M4y = 90.784x0.79530.969114.1715 M5y = 103.43x0.73550.964117.2075 pc 2 M1y = 85.893x0.82220.962615.7454 M2105.46x0.72270.965515.2220 M3y = 81.186x0.83220.977012.3854 M4y = 77.802x0.90480.960014.4513 M5y = 91.489x0.76770.964715.5911

BoneMeasurementequationr2see pc 3

M1y = 56.832x0.95110.961215.4095 M2y = 77.57x0.79050.964914.2249 M3y = 47.155x0.89470.968813.9942 M4y = 70.661x0.82790.922421.9828 M5y = 81.658x0.75010.966713.2195 pu 7 M1y = 72.173x0.83020.965016.0456 M2y = 76.775x0.77810.962714.5925 M3y = 55.136x0.79090.964514.6216 M4y = 63.831x0.88120.970313.3459 M5y = 81.749x0.71840.952615.9994

BoneMeasurementequationr2see pu 6

M1y = 90.365x0.97670.960216.0636 M2y = 103.31x1.06840.890727.8399 M3y = 209.23x0.85650.813935.4401 M4y = 97.379x0.89960.936119.9379 M5y = 103.16x0.92810.945719.7091 hpM1y = 105.9x0.9360.962015.8317 M2y = 108.85x1.13310.957417.2272 M3y = 33.944x0.91930.976912.3732

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measurements with the lowest r² are the M3 of the premaxilla (0.79), and the M2 of the maxilla (0.74).

taking all the M2 measurements of the vertebrae for one individual, we built a GRP for three different specimens of E. affinis (Fig. 4). We observed that the vertebral diameters (M2) are very homogeneous among the last precaudal and the first caudal vertebrae (rank 5 to 29). The profile for E. lineatus is very similar (Fig. 4: dot-line) as is the one for E. alletteratus (Desse and Desse-Berset, 1994: 72).

Note, however, that the diameter of the last caudal is higher in E. lineatus, a fact that could be linked to the hyperostotic condition of the preural vertebrae in this species.

The GRP allows to obtain a rather good estimate of the length and weight of an individual, even when it is not possible to assign a precise rank to an isolated vertebra from the median part of the backbone (Desse et al., 1989).

However, we have to contrast these results after observ- ing the standard error of estimate (see), which indicates the prediction error. Here, we have a large ranging of see values (Tabs III, IV). In E. affinis, the majority of the length- length relationships presented see values oscillating around 37; for E. lineatus, the see values obtained were lower than those obtained for E. affinis, around 18.

diScuSSion And concluSion

When we compare our length-weight relationship results with the previously published data, we can see a great simi- larity between the equations values (Tab. V). For E. affin- is, our results are very close to those of sivasubramaniam (1966) and Silas (1967) for the Indian waters, with an ‘a’

value close to 0.00001 (10^-5) and a ‘b’ value close to 3.06, indicating an isometric growth. For E. lineatus our allometric coefficient ‘b’ value, is a little lower than the one given by Klawe and Calkins (1965) and schaefer (1982). Finally, if we compare these results with those obtained for the third species, Euthynnus alleteratus,

which lives in the Atlantic Ocean, we observe a similar trend. Dif- ferences in shape may be due to the overall health of the fish or to ecological differences in the different areas. Collections made from different locations would definitely give a better picture of the general growth pattern of Euthynnus species.

In this article, we have presented regression equations, which allow the estimation of the length and weight of E. affinis and E. lin- eatus individuals from their iso-

lated bones. Some differences in determination coefficients indicate that some measurements are more appropriate than others for size reconstruction. However, all selected bones had at least one regression equation with a high r² (> 0.9) that should permit accurate estimates of the length or weight of Euthynnus individuals, and we recommend using the best- fitted regressions whenever possible.

similar work has previously been done by Desse and Desse-Berset (1994) on E. alletteratus using dentary measurements for size reconstruction of archaeological remains from the Cape Andreas Kastros site (Cyprus). As they used a linear model the results are not directly comparable, but the GRP curve they present is very similar to the one of E. affinis. Indeed, as all Euthynnus species have a very sim- ilar shape it is likely that our models can also be used for E. alletteratus.

the data presented here should facilitate reconstructions of diet and feeding behaviour of piscivorous species, including past humans, and help reconstruct fishing activities and human impact on neritic scombrids at least at a regional scale.

Acknowledgements. – We would like to thank Salem el-Ghazali, Khamis Nasser, Héctor Parrales, Cruz Elías Pincay, Enrique Toro, Elena Maini and many other fishermen for their help in catching the fish. Eric Pellé and the ‘Service des Préparations Ostéologiques et taxidermiques’ of the MNHN for his help in the preparation of the skeletons. Thanks are also due to Gabriela Prestes Carneiro for her advice, Alice Diaz Chauvigné, and Jill Cucchi for copy-editing.

RefeRenceS

BéArez P., 1996. – Comparaison des ichtyofaunes marines actuelle et holocène et reconstitution de l’activité halieutique dans les civilisations précolombiennes de la côte du Manabí sud (équateur). Unpubl. Ph.D. dissertation. Paris: Muséum national d’Histoire naturelle.

Table V. – Fork length (mm) to weight (g) equation parameters for the three species of Euthyn- nus.

species Geographic area reference ‘a’ value ‘b’ value

E. affinis Indian Ocean Morrow, 1954 0.000018 2.9630

E. affinis Indian Ocean sivasubramaniam, 1966 0.000013 3.0249

E. affinis Indian Ocean silas, 1967 0.000013 3.0287

E. affinis India James et al., 1993 0.000021 2.9500

E. affinis India rohit et al., 2012 0.000033 2.8890

E. affinis Oman Present study 0.000010 3.0635

E. lineatus Eastern Pacific Klawe and Calkins, 1965 0.000011 3.0817 E. lineatus Eastern Pacific schaefer, 1982 0.000011 3.0683 E. lineatus Ecuador, Eastern Pacific Present study 0.000020 2.9982 E. alleteratus turkey, Mediterranean sea Kahraman and Oray, 2001 0.000090 2.7256 E. alleteratus tunisia, Mediterranean sea Hajjej et al., 2009 0.000025 2.9264

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BEAREz P. & LUNNISS R., 2003. – Scombrid fishing at Salango (Manabí, Ecuador) during the first millennium BC. In: Proceed- ings of the 12^th meeting of the Fish Remains Working Group of the International Council for Archaeozoology, 4-8 Sep. 2003, Guadalajara, Mexico (Guzmán A.F., Polaco O.J. & Aguilar F.J., eds), pp. 27-32.

BEAREz P., GAy P. & LUNNISS R., 2012. – Sea fishing at Salan- go (Manabí Province, Ecuador) during the Middle Formative Machalilla phase. Lat. Am. Antiq., 23(2): 195-214.

BEAREz P., MEUNIER F.J. & KACEM A., 2005. – Description morphologique et histologique de l’hyperostose vertébrale chez la thonine noire, Euthynnus lineatus (teleostei : Perciformes : scombridae). Cah. Biol. Mar., 46(1): 21-28.

BeeCH M.J., 2004. – In the Land of the Ichthyophagi: Modelling Fish Exploitation in the Arabian Gulf and Gulf of Oman from the 5^th millennium BC to the Late Islamic period. 315 p.

Oxford: Archeopress.

BRILL R.W., 1994. – A review of temperature and oxygen toler- ance studies of tunas pertinent to fisheries oceanography, move- ment models and stock assessments. Fish. Oceanogr., 3(3):

204-216.

CAsteeL r.W., 1974. – A method for estimation of live weight of fish from the size of skeletal elements. Am. Antiq., 39(1):

94-98.

COLLETTE B.B. & NAUEN C.E., 1983. – scombrids of the world. An annotated and illustrated catalogue of tunas, macker- els, bonitos and related species known to date. FAO species catalogue. FAO Fish. Synop., 125(2): 1-137. rome: FAO.

Desse J., 1984. – Propositions pour une réalisation collective d’un corpus: fiches d’identification et d’exploitation métrique du squelette des poissons. In: 2^e rencontres d’archéo-ichtyologie (N. Desse-Berset, ed.). Notes et monographies techniques, 16:

67-86. Valbonne: CRA-CNRS.

Desse J. & Desse-Berset N., 1994. – Osteometry and fishing strategies at Cape Andreas Kastros (Cyprus, 8^th millennium BP). Ann. Mus. R. Afr. Cent., ser. 8, sci. zool., 274: 69-79.

DESSE J., DESSE-BERSET N. & ROCHETEAU M., 1989. – Les profils rachidiens globaux. Reconstitution de la taille des poissons et appréciation du nombre minimal d’individus à partir des pièces rachidiennes. Rev. Paléobiol., 8(1): 89-94.

DyE T.S. & LONGENECKER K.R., 2004. – Manual of Hawaiian fish remains identification based on the skeletal reference collection of Alan C. ziegler and including otoliths. special Publi- cation, 1: 1-143. Honolulu: society for Hawaiian Archaeology and Bishop Museum Press.

GODSIL H.C., 1954. – A descriptive study of certain tuna-like fishes. Fish Bull., 97: 1-188.

GOULD s.J., 1966. – Allometry and size in ontogeny and phylog- eny. Biol. Rev., 41(4): 587-638.

HAJJEJ G., HATTOUR A., ALLAyA H., JARBOUI O. & BOUAIN A., 2009. – sex-ratio, relation taille-masse et coefficient de condition de la thonine commune Euthynnus alletteratus (Rafi- nesque, 1810) des côtes tunisiennes. Bull. INSTM, 36: 39-44.

JAMES P.S.B.R., PILLAI P.P., PILLAI N.G.K., JAyAPRAKASH A.A., GOPAKUMAR G., KASIM M., SIVADAS M. & KOyA K.P.s., 1993. – Fishery, biology and stock assessment of small tunas. In: Tuna Research in India (Sudarsan D. & John M.E., eds), pp. 123-148. Bombay: Fishery Survey of India.

KAHRAMAN A.E. & ORAy I.K., 2001. – the determination of age and growth parameters of Atlantic little tuny Euthynnus alleteratus (rafinesque, 1810) in turkish waters. Collective Vol. Sci. Pap., ICCAT, 52: 719-732.

KISHINOUyE K., 1923. – Contributions to the comparative study of the so-called scombroid fishes. J. Coll. Agric. Imp. Univ.

Tokyo, 8(3): 293-475.

KLAWE W.L. & CALKINS T.P., 1965. – Length-weight relationship of black skipjack tuna Euthynnus lineatus. Calif. Fish Game, 51(3): 214-216.

KULBICKI M., GUILLEMOT N. & AMAND M., 2005. – A general approach to length-weight relationships for New Caledoni- an lagoon fishes. Cybium, 29(3): 235-252.

LAMBRIDES A.B. & WEISLER M.I., 2017. – Late Holocene Marshall Islands archaeological tuna records provide proxy evidence for eNsO variability in the western and central Pacif- ic Ocean. JICA. doi: 10.1080/15564894.2017.1315350.

LANDAU R., 1965. – Determination of age and growth rate in Euthynnus alletteratus and E. affinis using vertebrae. Rapp. P.

V. Réun. Comm. Int. Explor. Sci. Mer Medit., 18(2): 241-243.

Le CreN e.D., 1951. – the length-weight relationship and sea- sonal cycle in gonad weight and condition in the perch (Perca fluviatilis). J. Anim. Ecol., 20(2): 201-219.

LIDOUR K., VORENGER J. & BéAREz P., 2018. – size and weight estimations of the spangled emperor (teleostei:

Lethrinidae: Lethrinus nebulosus) from bone measurements elucidate the fishing grounds exploited and ancient seasonality at Akab (United Arab Emirates). Int. J. Osteoarchaeol., doi:

10.1002/oa.2683.

MANSUETI R.J. & MANSUETI A.J., 1962. – Little tuna, Euthyn- nus alletteratus, in northern Chesapeake Bay, Maryland, with an illustration of its skeleton. Chesapeake Sci., 3(4): 257-62.

MARTíNEz M.F., JIMéNEz M. & COOKE R., 2009. – Fishing at pre-Hispanic settlements on the Pearl Island Archipelago (Pan- ama, Pacific), II: Bayoneta Island (900-1300CE). In: Proceed- ings of the 15^th meeting of the Fish Remains Working Group of the International Council for Archaeozoology, 3-9 Sep. 2009, Poznan and torun, Poland (Makowiecki D., Hamilton-Dyer s., Riddler I., Trzaska-Nartowski N. & Makohonienko M., eds), pp. 172-178.

MORALES A. & ROSENLUND K., 1979. – Fish bone measurements: An attempt to standardize the measuring of fish bones from archaeological sites. 48 p. Copenhagen: zoological Muse- MOrrOW J.e., 1954. – Data on dolphin, yellowfin tuna and little um.

tuna from east Africa. Copeia, 1954(1): 14-16.

MULHIA-MELO A.F., 1980. – Synopsis of biological data on the black skipjack tuna, Euthynnus lineatus, Kishinouye, 1920. In:

synopses of Biological Data on eight species of scombrids (Bayliff W.H., ed.). IATTC Special Report n° 2. 520 p. La Jolla:

IATTC.

PRESTES-CARNEIRO G. & BéAREz P., 2017. – swamp-eel (Synbranchus spp.) fishing in Amazonia from pre-Columbian to present times. J. Ethnobiol., 37(3): 380-397.

REITz E. J., QUITMyER I.R., HALE H.S., SCUDDER S.J. &

WING E.S., 1987. – Application of allometry to zooarchaeolo- gy. Am. Antiq., 52(2): 304-317.

RICKER W.E., 1958. – Handbook of computation for biological studies of fish populations. Bull. Fish Res. Board Can., 119:

1-300.

ROHIT P., CHELLAPPAN A., ABDUSSAMAD E.M., JOSHI K.K., KOyA K.P.S., SIVADAS M., GHOSH S., MARRATHI- NAM A.M.M., KEMPARAJU S., DHOKIA H.K., PRAKAS- AN D. & BENI N., 2012. – Fishery and bionomics of the little tuna, Euthynnus affinis (Cantor, 1849) exploited from Indian waters. Indian J. Fish., 59(3): 37-46.

sCHAeFer K.M., 1982. – Length-weight relationship of the black skipjack, Euthynnus lineatus. IATTC Int. Rep., 17: 1-15.

sCHAeFer K.M., 1987. – reproductive biology of black skipjack, Euthynnus lineatus, an eastern Pacific tuna. IATTC Bull., 19(2): 166-260.

(13)

SILAS E.G., 1967. – Tuna fishery of the Tinnevelly coast, Gulf of Mannar. Mar. Biol. Ass. India Symp. Ser., 1: 1083-1120.

SIVASUBRAMANIAM K., 1966. – Distribution and length-weight relationship of tunas and tuna-like fishes around Ceylon. Bull.

Fish. Res. Stn, Ceylon, 19: 27-46.

TEISSIER G., 1948. – La relation d’allométrie. sa signification statistique et biologique. Biometrics, 4(1): 14-53.

THIEREN E. & VAN NEER W., 2016. – New equations for the size reconstruction of sturgeon from isolated cranial and pecto- ral girdle bones. Int. J. Osteoarchaeol., 26: 203-210.

UERPMANN H.P. & UERPMANN M., 2003. – stone Age sites and their Natural environment the Capital Area of Northern Oman. Part III. 266 p. Wiesbaden: Dr. Ludwig Reichert.

VALEIRAS X., MACíAS D., GóMEz M.J., LEMA L., GODOy D., DE URBINA J.O. & DE LA SERNA J.M., 2008. – Age and growth of Atlantic little tuna (Euthynnus alletteratus) in the western Mediterranean sea. Collect. Vol. Sci. Pap. ICCAT, 62(5): 1638-1648.

WING E.S., 2001. – The sustainability of resources used by native Americans on four Caribbean islands. Int. J. Osteoarchaeol., 11: 112-126.