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Der Kaphummer (Homarinus capensis), auch Kap-Hummer geschrieben, ist eine Art der Zehnfußkrebse aus der monotypischen Gattung Homarinus. Bis 1995 war diese Art Teil der Gattung Hummer (Homarus), wurde aber u. a. aufgrund ihrer wesentlich kleineren Körpergröße zu einer neuen Gattung ausgestellt.[1] Der Name „Homarinus“ bedeutet „hummerähnlich“, das Artepitheton bezieht sich auf die Herkunft der Art, die Gewässer um das Kap der Guten Hoffnung.
Der Kaphummer erreicht Körperlängen von 8 bis 10 cm, der Carapax ist dabei 4 bis 5 cm lang.[2] Seine Farbe ist korallenrot bis bräunlich gelb.
Der Körperbau ähnelt dem der Hummer (Homarus). Im Gegensatz zu jenen sind die Scheren der ersten Schreitbeine deutlich behaart. Die großen Scheren am ersten Beinpaar haben wegen der länglichen Carpus ein langgezogenes Erscheinungsbild. Während das Rostrum bei Amerikanischen und Europäischen Hummer zur Spitze hin aufrichtet ist, ist es beim Kaphummer abgeflacht und mit kleineren seitlichen Dornen versehen. Die Gonoporen sind relativ groß, weshalb vermutet wird, dass die Eier nicht nur wesentlich größer als bei anderen Hummern sind, sondern auch weniger zahlreich.[3]
Trotz ihrer morphologischen Ähnlichkeiten sind die Gattungen Homarus und Homarinus keine Schwestergruppen. Phylogenetische Untersuchungen weisen vielmehr darauf hin, dass eine Konvergenz vorliegt.[4]
Das natürliche Verbreitungsgebiet des Kaphummers erstreckt sich an der südafrikanischen Küste von Dassen Island bei Kapstadt im Westen bis Haga Haga in der Provinz Ostkap im Osten.[3] Dort lebt er in eher flachen Küstengewässern auf steinigem Grund.[2] Der Kaphummer wird nicht befischt und ist eine äußerst seltene Art, die vom Aussterben bedroht ist.[5]
Die Erstbeschreibung des Kaphummers erfolgte durch Johann Friedrich Wilhelm Herbst im Jahr 1792 als Cancer (Astacus) capensis. Synonyme sind Astacus fulvus Fabricius, 1793, Homarus fulvus Weber, 1795, Astacus capensis Latreille, 1802 und Cancer (Astacus) fulvus Turton, 1806.[2]
Der Kaphummer (Homarinus capensis), auch Kap-Hummer geschrieben, ist eine Art der Zehnfußkrebse aus der monotypischen Gattung Homarinus. Bis 1995 war diese Art Teil der Gattung Hummer (Homarus), wurde aber u. a. aufgrund ihrer wesentlich kleineren Körpergröße zu einer neuen Gattung ausgestellt. Der Name „Homarinus“ bedeutet „hummerähnlich“, das Artepitheton bezieht sich auf die Herkunft der Art, die Gewässer um das Kap der Guten Hoffnung.
The Cape lobster, Homarinus capensis, is a species of small lobster that lives off the coast of South Africa, from Dassen Island to Haga Haga. Only a few dozen specimens are known, mostly regurgitated by reef-dwelling fish. It lives in rocky reefs, and is thought to lay large eggs that have a short larval phase, or that hatch directly as a juvenile. The species grows to a total length of 10 cm (3.9 in), and resembles a small European or American lobster; it was previously included in the same genus, Homarus, although it is not very closely related to those species, and is now considered to form a separate, monotypic genus – Homarinus. Its closest relatives are the genera Thymops and Thymopides.
The Cape lobster is endemic to South Africa. It occurs from Dassen Island, Western Cape in the west to Haga Haga, Eastern Cape in the east, a range of 900 kilometres (560 mi).[5] Most of the known specimens were regurgitated by fish caught on reefs at depths of 20–40 metres (66–131 ft).[5] This suggests that the Cape lobster inhabits rocky substrates, and may explain its apparent rarity, since such areas are not amenable to dredging or trawling, and the species may be too small to be retained by lobster traps.[5]
Homarinus capensis is considerably smaller than the large northern lobsters of the Atlantic Ocean, Homarus gammarus (the European lobster) and Homarus americanus (the American lobster), at 8–10 centimetres (3.1–3.9 in) total length, or 4–5 cm (1.6–2.0 in) carapace length.[4][6] Accounts of the colouration of H. capensis are very variable, from tawny, red or yellow to "a rather dark olive", similar to Homarus gammarus.[7]
Homarinus and Homarus are considered to be the most plesiomorphic genera in the family Nephropidae.[8] Nonetheless, the Cape lobster differs from Homarus in a number of characters. The rostrum of the Cape lobster is flattened, while that of Homarus is rounded in section, and curves upwards at the tip.[5] The three pairs of claws[Note 1] are covered with hairs in Homarinus, while those of Homarus are hairless.[4] The telson tapers along its length in Homarus, but has sides which are nearly parallel in Homarinus.[5] Although no egg-bearing females have been collected, the gonopores (openings of the oviducts) of female Cape lobsters are much larger than those of Homarus gammarus and Homarus americanus.[5] This is thought to indicate that Homarinus bears fewer, larger eggs than Homarus, and that either the larvae develop quickly into juveniles after hatching, or that the eggs hatch directly into juveniles.[5][10]
Cape lobsters are elusive and rare, with only fourteen specimens having been collected between 1792 (the date of its first description) and 1992.[7] These include five males in the collections of the South African Museum (Cape Town), two in the Natural History Museum (London), one in each of the East London Museum, the Rijksmuseum van Natuurlijke Historie (Leiden) and the Albany Museum (Grahamstown), and one male and one female in the Muséum national d'histoire naturelle (Paris).[6] In 1992, a Cape lobster was discovered at Dassen Island, and the publicity the find generated resulted in more than 20 additional specimens being reported.[5]
The Cape lobster was first described by Johann Friedrich Wilhelm Herbst in 1792 as Cancer (Astacus) capensis.[9][11] It was independently described in 1793 by Johan Christian Fabricius as Astacus flavus, possibly based on the same type specimen.[9] When Friedrich Weber erected the genus Homarus in 1795, he included Fabricius' species in it, but this placement was not followed by later authors.[9] The species reached its current classification in 1995, when the monotypic genus Homarinus was erected by Irv Kornfield, Austin B. Williams and Robert S. Steneck.[7]
While analyses of morphology suggest a close relationship between Homarinus and Homarus, molecular analyses using mitochondrial DNA reveal that they are not sister taxa.[8] Both genera lack ornamentation such as spines and carinae, but are thought to have reached that state independently, through convergent evolution.[8] The closest living relative of Homarus is Nephrops norvegicus, while the closest relatives of Homarinus are Thymops and Thymopides.[8]
The Cape lobster, Homarinus capensis, is a species of small lobster that lives off the coast of South Africa, from Dassen Island to Haga Haga. Only a few dozen specimens are known, mostly regurgitated by reef-dwelling fish. It lives in rocky reefs, and is thought to lay large eggs that have a short larval phase, or that hatch directly as a juvenile. The species grows to a total length of 10 cm (3.9 in), and resembles a small European or American lobster; it was previously included in the same genus, Homarus, although it is not very closely related to those species, and is now considered to form a separate, monotypic genus – Homarinus. Its closest relatives are the genera Thymops and Thymopides.
Homarinus capensis
Le homard du Cap (Homarinus capensis), est un petit homard des côtes Sud-africaines, entre Le Cap et East London. Cette espèce était incluse dans le genre Homarus avant qu'il ne soit décrit son propre genre Homarinus en 1995[1].
Les homards du Cap sont rares. Seuls 14 spécimens, dont une seule femelle, furent collectés entre 1792 (année de la première description) et 1992. En 1992, un spécimen vivant fut découvert sur l’île de Dassen, ainsi qu'un autre mort près de East London. La publicité faite autour de ces découvertes permit de recenser 2 autres individus.
Après la découverte de 3 individus vivants en avril et mai 1997, les seuls au monde, l'aquarium de East London espère maintenant élever l'espèce à partir de cette femelle et des 2 mâles.
Comme les espèces du genre Homarus, H. capensis a des pinces spécialisées, une pour découper et l'autre pour écraser.
Homarinus capensis
Le homard du Cap (Homarinus capensis), est un petit homard des côtes Sud-africaines, entre Le Cap et East London. Cette espèce était incluse dans le genre Homarus avant qu'il ne soit décrit son propre genre Homarinus en 1995.
Les homards du Cap sont rares. Seuls 14 spécimens, dont une seule femelle, furent collectés entre 1792 (année de la première description) et 1992. En 1992, un spécimen vivant fut découvert sur l’île de Dassen, ainsi qu'un autre mort près de East London. La publicité faite autour de ces découvertes permit de recenser 2 autres individus.
Après la découverte de 3 individus vivants en avril et mai 1997, les seuls au monde, l'aquarium de East London espère maintenant élever l'espèce à partir de cette femelle et des 2 mâles.
Comme les espèces du genre Homarus, H. capensis a des pinces spécialisées, une pour découper et l'autre pour écraser.
Homarinus capensis is een kreeftensoort uit de familie van de Nephropidae.[2] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1792 door Herbst.
Bronnen, noten en/of referenties
Homarinus er en slekt innenfor hummerfamilien - store og ofte spiselige krepsdyr som tilhører den meget tallrike og viktige gruppen av tifotkreps. Hummere lever i saltvann som bunndyr nede på havbunnen. Denne slekten er en av 17 hummer-slekter, og har 1 art - kapphummer.
Taksonomien til storkreps er komplisert og under stadig revisjon. Det er generelt omstridt å fin-inndele organismer taksonomisk. En moderne oppdatering av systematikken gis her med basis i WoRMS-databasens systematikk fra 2013.[1].
Homarinus er en slekt innenfor hummerfamilien - store og ofte spiselige krepsdyr som tilhører den meget tallrike og viktige gruppen av tifotkreps. Hummere lever i saltvann som bunndyr nede på havbunnen. Denne slekten er en av 17 hummer-slekter, og har 1 art - kapphummer.
Tôm hùm Hảo Vọng (danh pháp khoa học: Homarinus capensis) là một loài tôm hùm nhỏ sống ven bờ biển của Nam Phi, từ đảo Dassen tới Haga Haga. Trước đây người ta xếp chúng vào chi Homarus, nhưng từ năm 1995 chúng được xếp vào một chi riêng là Homarinus. Những họ hàng gần nhất của chúng là Thymops và Thymopides. Tôm hùm Hảo Vọng rất hiếm và khó bắt, kể từ năm 1792 (khi bắt đầu mô tả chúng) cho đến năm 1992 chỉ mới đánh bắt được 14 con, trong đó có một con cái. Sau khi phát hiện ra ba cá thể còn sống năm 1997, là những mẫu còn sống duy nhất trên thế giới, hiện nay Khu bể nuôi Đông London hy vọng sẽ nhân giống được loài này.
Tôm hùm Hảo Vọng (danh pháp khoa học: Homarinus capensis) là một loài tôm hùm nhỏ sống ven bờ biển của Nam Phi, từ đảo Dassen tới Haga Haga. Trước đây người ta xếp chúng vào chi Homarus, nhưng từ năm 1995 chúng được xếp vào một chi riêng là Homarinus. Những họ hàng gần nhất của chúng là Thymops và Thymopides. Tôm hùm Hảo Vọng rất hiếm và khó bắt, kể từ năm 1792 (khi bắt đầu mô tả chúng) cho đến năm 1992 chỉ mới đánh bắt được 14 con, trong đó có một con cái. Sau khi phát hiện ra ba cá thể còn sống năm 1997, là những mẫu còn sống duy nhất trên thế giới, hiện nay Khu bể nuôi Đông London hy vọng sẽ nhân giống được loài này.
