Embryo development of Lamnid Sharks

Embryo Development of Lamnid Sharks
Dimensions are linked to photographs if available. A slide show (needing an update) using available photos of lamnid embryos (across species) starts with the smallest shortfin mako embryo (~ 3 cm TL, still inside the eggcase). Next is a 6 cm TL porbeagle embryo which hatched and is ready to feed on eggs inside the uterus and so forth. Links to embryos/litters of individual species are given in the headers of the table if available. For porbeagle see also page by Richard Lord (only a few pictures are included here). See also detailed photos on anatomy of salmon shark embryos by Lohberger (1910). Spring begins on Mar 22 and 22 October in Northern and Southern Hemispheres, respectively.
Stage	Porbeagle, Lamna nasus	Salmon shark, L. ditropis	Longfin mako, Isurus paucus	Shortfin mako, I. oxyrinchus	White shark, Carcharodon carcharias	Comments
GSI of mature females	max. 6.3 kg (3.6%), Francis & Stevens 2000		0.46% (spent), Gilmore 1983	0.1-5.0%; Mollet et al. 2000	0.48%, Amorim &Arfelli 1992; 2.0 kg, Bruce 1992	Ovary mass as % of total mass
Diameter of ovarian eggs	1-6 mm, Swenander 1907; 1.5-4.7 mm, Francis & Stevens 2000		2-3 mm, Killam & Parsons 1986); 3-5 mm, Gilmore 1983	1-8 mm, Mollet et al. 2000	0.8-5.1 mm (?)
Size of blastodisc eggcase				3x10 cm, Mollet et al. 2000, blastodisc eggs are already in an early stage of development)	Not sure if blastodisc or nutritive eggcases, awaiting size estimate.	Eggcase with fertile eggs
No. & size of nutritive eggcases	Over 40 5.0x1.5 cm with 21-28 eggs of diameter 4-5 mm, Swenander 1907			Over 40 per uterus 3x5 cm with 16-20 eggs per capsule	3 sizes, a typical large one was 19 cm x 3.5 cm x 3.0 cm & weighed 103 g, Uchida et al. 1987	Eggcase with nutritive eggs
TL of embryo with yolk-sac				ca. 3 cm TL, Mollet et al. 2000 (embryo in center was removed from eggcase for photo)		Embryo is nourished by yolk sac
TL of embryo when no yolk sac left	5.5-6.0 cm, Jan. 1904, Swenander 1907			est. 5-6 cm, Mollet et al. 2000	~10 cm embryo, dorsal view, lateral view. Not sure if embryo has hatched or was still inside eggcase.	Embryo starts feeding on nutritive eggs
TL of embryo with fangs, A. Duhamel	9.6 cm (A), Francis & Stevens 2000
TL of embryos,	~10 cm, Richard Lord					Also shows nutritive eggcases
TL of embryos with yolk stomach	20.7 &19.8 cm (A) Francis & Stevens 2000
TL of embryo with large yolk stomach	30.0 cm, Swenander 1907			25-31 cm, Mollet at al. 2000
TL & M of embryo with large yolk stomach	34.2 cm (B), Francis & Stevens 2000			36.1 cm; 0.8 kg Sanzo 1912, Mollet et al. 2000
TL & M of embryos with large yolk stomach	40.3 cm (C), Francis & Stevens 2000			42.3-49.6 cm, Gilmore 1999 Fig. 1	42.5 cm Hua Hsun HSU pers. comm.
TL & M of embryos with large yolk stomach		52.5 cm 39.3 cm PCL, Otake T. pers. comm.		50.4-54.0 cm; 1.44-2.37 kg Mollet et al. 2000	50-60 cm Victor Lin pers. comm.
TL & M of embryos with large yolk stomach	58.0 cm (D), Francis & Stevens 2000	55.3 cm, 2.68 kg Lohberger 1910		56.8-62.0 cm, 2.1-2.8 kg Mollet et al. 2000
TL & M of large prenatal embryo	78 cm, 67 cm FL, Francis & Stevens 2000			71.2 cm, Mollet et al. 2002	145 cm, 26.1 kg; 151 cm, 32.4 kg Francis 1996, Uchida et al. 1996
TL & M at birth		65-70 cm, Paust and Smith 1986	97-125 cm, 5.2-12kg	70 cm, Mollet et al. 2000	120-150 cm, 12-32 kg, Francis 1996
TL of smallest free-swimmer	68 cm (58 cm FL), Francis & Stevens 2000	65 cm, Paust and Smith 1986		69 cm TL. Pratt and Casey 1983	122 cm TL, Francis 1996
Time of parturition		May, Paust and Smith 1986		late Win to early Spr, Mollet et al. 2002	late Spr-Sum , Francis 1996, Klimely 1985	Time of birth
Gestation period	8-9 mo, Francis & Stevens 2000	ca. 1 yr, Paust 1987		15-18 mo, 20 mo, Mollet et al. 2000, Christiansen et al. 2014	> 1 yr, Mollet et al. 2000	Time from fertilization to birth
Reproductive cycle	1 yr (Fr)			3 years, Mollet et al 2002	3 yr? Mollet & Cailliet 2002	Gestation plus resting time
Litter size	2-5	up to 4, Paust 1987	2-8, Casey 1986	4-25, Mollet et al. 2000	4-14, (7-10 documented), Francis 1996	# of embryos in a litter
Mating period				late Sum-Fall?, Mollet et al. 2000	Nov-Feb (Australasia), Francis 1996
Evidence of sperm storage				No, Stevens 1983
Stage	Porbeagle, Lamna nasus	Salmon shark, L. ditropis	Longfin mako, Isurus paucus	Shortfin mako, I. oxyrinchus	White shark, Carcharodon carcharias	Comments

Embryo Development of Lamnid Sharks

Dimensions are linked to photographs if available. A slide show (needing an update) using available photos of lamnid embryos (across species) starts with the smallest shortfin mako embryo (~ 3 cm TL, still inside the eggcase). Next is a 6 cm TL porbeagle embryo which hatched and is ready to feed on eggs inside the uterus and so forth. Links to embryos/litters of individual species are given in the headers of the table if available. For porbeagle see also page by Richard Lord (only a few pictures are included here). See also detailed photos on anatomy of salmon shark embryos by Lohberger (1910). Spring begins on Mar 22 and 22 October in Northern and Southern Hemispheres, respectively.

Stage

Porbeagle, Lamna nasus

Salmon shark, L. ditropis

Longfin mako, Isurus paucus

Shortfin mako, I. oxyrinchus

White shark, Carcharodon carcharias

Comments

GSI of mature females

max. 6.3 kg (3.6%), Francis & Stevens 2000

0.46% (spent), Gilmore 1983

0.1-5.0%; Mollet et al. 2000

0.48%, Amorim &Arfelli 1992;
2.0 kg, Bruce 1992