Family Squalidae: The Main Features

Topic: Family Words: 1596 Pages: 4

The main features of the taxon include their size, from small to medium (Francis, Stevens, & Las, 1988). They have a sharp spine and two dorsal fins. This family comprises of sharks in the order of Squaliformes (Snene et al., Springer, 1959). The main feature of the representatives of this species is the fact that they have an equal amount of teeth in their upper row when comparing the anterior and succeeding rows (Springer, 1959). Some of the common representatives include spiny dogfishes and sleeper sharks. Important contributions to the discovery of Family Squalidae were made by Springer (1959), Springer, and Burgess (1985), Fisher et al. (2006), and others, who described the characteristics of the species representatives.

As for the diet, the Family Squalidae predominantly feed on herring, squid, and other small fish, for example, herring Sprattus fuegensis and squid Loligo gahi (Laptikhovsky et al., 2001). The lifecycle of the Family Squalidae, the males and females mate in the offshore waters (Springer, 1959). The female specimens have ovulation and produce embryos right after parturition (Fischer et al., 2006). However, the females reach maturation within their 18th to 21st years of life, while males reach it after 11 years. The fertilized eggs have a shell that should protect the embryo. The embryos spend approximately 2 years in the womb and in general, these species live from 20 to 24 years. Family Squalidae is geographically distributed along the Pacific and Atlantic coasts, although there are some papers describing the specimens found in the Baltic Sea and other locations (Więcaszek et al., 2018).

Hence, the annotated bibliography features many examples of the Family Squalidae, such as Squalus acutipinnis Regan, Lantensharks, Squalus mitsukurii, Cirrhigaleus asper among others (de Viana et al., Benz, 1991; Fisher et al., 2006). The papers in the annotated bibliography were primary sources describing either the collective characteristics of this family or detailing the newly found specimens and representatives of the species.

Annotated Bibliography

Benz, G. W. (1991). Description of some larval stages and augmented description of adult stages of Albionella etmopteri (Copepoda: Lernaeopodidae), a parasite of deep-water Lanternsharks (Etmopterus: Squalidae). The Journal of Parasitology, 77(5), 666–674. Web.

Benz focuses on describing the larval stages of the Family Squalidae, which is the stage of development that many animals have right after birth and before they reach their adult form. This description is based on the Lantensharks, one of the representatives of the family in question. The specimens of Lanternsharks were observed in the deep waters of Japan and South Africa.

Bigelow, H., Farfante, I., & Schroeder, W. (2019). Lancelets, cyclostomes, sharks. New Heaven, CT: Yale University Press.

In the chapter “Family Squalidae” the authors describe the primary characteristics of this family, such as the key characteristics, characters, genera, and others. The authors note that the specimens from this family typically have teeth with 1 cusp and two dorsal spines with fins. The teeth are similar in the upper and lower jaws.

de F. Viana, S. T., & de Carvalho, M. R. (2016). Redescription of Squalus acutipinnis Regan, 1908, a valid species of spiny Dogfish from Southern Africa (Chondrichthyes: Squaliformes: Squalidae). Copeia, 104(2), 539–553.

This author provides a redescription of the paper published in 1908 with the characteristics of the dog shark with a spine, Squalus acutipinnis Regan. The reason for the redescription is the author’s new findings based on the specimens found in South Africa. Hence, this paper provides some of the general characteristics and taxonomy of the family and compares them to those of the newly discovered specimens.

Fischer, A., Veras, D., Hazin, F., Broadhurst, M., Burgess, G., & Oliveira, P. (2006). Maturation of Squalus mitsukurii and Cirrhigaleus asper (Squalidae, Squaliformes) in the southwestern equatorial Atlantic Ocean. Journal of Applied Ichthyology, 22(6), 495-501.

The author focuses on describing the process of maturation for the specimens of the Family Squalidae. Both female and male species were captured to observe the process of their maturation from the species Squalus mitsukurii and Cirrhigaleus asper, and the authors observed over three hundred specimens. Generally, the size of the female Squalidae was larger when compared to the males, and the females had ovulation immediately after parturition.

Francis, M., Stevens, J. D. & Last, P. R. (1988) New records of Somniosus (Elasmobranchii: Squalidae) from Australasia, with comments on the taxonomy of the genus. New Zealand Journal of Marine and Freshwater Research, 22(3), 401-409.

The authors focus on the description of the family’s taxonomy. They describe the morphometrics, tooth shape and characteristics, and dermal denticles.

Laptikhovsky, V., Arkhipkin, A., & Henderson, A. (2001). Feeding habits and dietary overlap in spiny dogfish Squalus acanthias (Squalidae) and narrowmouth catshark Schroederichthys bivius (Scyliorhinidae). Journal of the Marine Biological Association of the United Kingdom, 81(6), 1015-1018.

This paper describes some of the essential components of diet and feeding habits that the Family Squalidae species have. The dogfish’s diet predominantly consists of herring and squid.

Snene, H., Rangel, L., Quilichini, Y., Santos, M., & Bahri, S. (2021). First description of Chloromyxum squali Gleeson and Adlard, 2012 (Myxozoa) in the Mediterranean Sea in a new host Squalus blainville (Chondrichthyes: Squalidae): morphological, ultrastructural and phylogenetic data. Parasitology Research, 20-23.

This paper is the first description of the Squalus blainville species from the family that contains morphological, phylogenetic, and ultrastructural data. Additionally, the paper features a description of parasites that infect the dogfish and their effect on the latter.

Springer, S. (1959). A new shark of the Family Squalidae from the Carolina continental slope. Copeia, 1959(1), 30-33.

Describes a newly discovered species from the Squalidad family, which is a Daenia . Provides a detailed overview of the habitat, taxonomy, and other important characteristics for the Daenia species, which typically inhabits the deepwater of Madeira, Portugal, Natal, Japan, and the Philippines. The particular specimen that the author writes about is from the Carolina continental slope.

Springer, S., & Burgess, G. H. (1985). Two new dwarf dogsharks (Etmopterus, Squalidae), found off the Caribbean Coast of Colombia. Copeia, 1985(3), 584–591. Web.

Similarly to the article published by Springler in 1959, this text describes a new species from the Family Squalidae. The US Fish and Wildlife research vessel has discovered new specimens of this family, near the Caribbean and Columbian costs. Some of the specimens discovered were already described by researchers, however, seven specimens were new and never described before.

Surhone, L. M., Tennoe, M. T., & Henssonow, S. F. (Eds.) (2010). Squalidae. New York, NY: Betascrip Publishing.

This book is a complete overview of the Family Squalidae consisting of several articles by researchers and edited into a collection that described the main characteristics of this family. The main information includes the taxonomy of the species, such as the size of dogfish sharks ranging from medium to small, or from 48 centimeters to 1.6 meters in length. The distinguishing characteristic of this family is the two dorsal fins with smooth spins, but no anal fin.

Tagliafico, A., Rangel, S., & Broadhurst, M. (2018). Maturation and reproduction of Squalus cubensis and Squalus cf. quasimodo (Squalidae, Squaliformes) in the southern Caribbean Sea. Ichthyological Research, 66(1), 1-8.

Tagliafico et al. (2018) describe the process of maturation for the two representatives of the Family Squalidae: Squalus cubensis and Squalus cf. quasimodo. These two representatives can be found in the Caribbean sea deep waters. Each female representative had a functioning uterus with a number of embryos ranging from one to five. However, the authors recommend further studies to examine the life history of the species.

White, W., Last, P., & Stevens, J. (2007). Cirrhigaleus australis n. sp., a new Mandarin dogfish (Squaliformes: Squalidae) from the south-west Pacific. Zootaxa, 1560(1), 19-30.

The authors describe the new species of the Family Squalidae, the Mandarin dogfish based on the representatives that were observed in the South East of Australia. Additionally, the authors make distinctions between their species and Cirrhigaleus australis, which previously were considered the same. However, the Madnarin goldfish has smaller eyes and dorsal-caudral space, pectoral fins, dorsal fins, and spinners. This work contributes to the understanding of the variations of the Family Squalidae’s representatives.

Więcaszek, B., Sobecka, E., Panicz, R., Keszka, S., Górecka, K., & Linowska, A. (2018). First record of the deep-water shark Etmopterus spinax (Chondrichthyes: Etmopteridae) from the southern Baltic Sea (Pomeranian Bay). Oceanologia, 60(3), 426-430.

This paper is a description of the first specimen of the Squalidae family that was observed in the Baltic Sea. The Etmopterus spinax or the velvet belly anternshark is a non-commercial species, which is usually found in the Mediterranean Sea or the North Atlantic, which previously has not been studied in-depth due to the lack of its commercial value. This particular specimen was a female with a length of 42.7 cm.

Viana, S. T., Carvalho, M. R., & Gomes, U. L. (2016). Taxonomy and morphology of species of the genus Squalus Linnaeus, 1758 from the Southwestern Atlantic Ocean (Chondrichthyes: Squaliformes: Squalidae). Zootaxa, 133(1):1-89.

This paper is a comprehensive description of the Family Squalidae’s taxonomy. The squalus genus generally has a complex taxonomy as it is challenging to morphologically differentiate these species.

Viana, S., & de Carvalho, M. (2018). Resurrection and redescription of the Southern Dogfish Squalus probatovi (Squalidae), a valid species from Angola. Journal of Ichthyology, 58(5), 617-632.

The authors focus on describing a medium-sized representative of the family, the Squalus probatovi. These specimens were found in the waters of Angola. The authors focus on describing the taxonomy and morphology of Squalus probatovi in comparison to the general characteristics of dogfishes.

References

Bigelow, H., Farfante, I., & Schroeder, W. (2019). Lancelets, cyclostomes, sharks. New Heaven, CT: Yale University Press.

Springer, S. (1959). A new shark of the Family Squalidae from the Carolina continental slope. Copeia, 1959(1), 30-33.

Springer, S., & Burgess, G. H. (1985). Two new dwarf dogsharks (Etmopterus, Squalidae), found off the Caribbean Coast of Colombia. Copeia, 1985(3), 584–591. Web.

Surhone, L. M., Tennoe, M. T., & Henssonow, S. F. (Eds.) (2010). Squalidae. New York, NY: Betascrip Publishing.

White, W., Last, P., & Stevens, J. (2007). Cirrhigaleus australis n. sp., a new Mandarin dogfish (Squaliformes: Squalidae) from the south-west Pacific. Zootaxa, 1560(1), 19-30.

Viana, S., & de Carvalho, M. (2018). Resurrection and redescription of the Southern Dogfish Squalus probatovi (Squalidae), a valid species from Angola. Journal of Ichthyology, 58(5), 617-632.