Ancistrocheirus, Gray, 1849

Arnold, Sam, Nos, David, Sáez-Liante, Raquel & Fernández-Álvarez, Fernando Á., 2025, Diversity in the squid family Ancistrocheiridae and description of a new family of the order Oegopsida (Cephalopoda), Zoological Journal of the Linnean Society 204 (3) : -

Ancistrocheirus miscellaneous specimens.

(Supporting Information, Tables S2, S 3)

Examined material

NHM 20240066, 1 sex unknown, 33 mm DML, 03/06/1930, South Africa, 33º 50′ 30′′ S, 15º 46′ 00′′ E, depth <1200 m. NHM 20240067, 1 sex unknown, 54 mm DML, 08/11/1966, Canary Islands , 28º 5′ 12′′ N, 14º 7′ 24′′ W, depth <100 m . NHM 20240068, 5 sex unknown, 33 mm DML, 27 mm DML, 23 mm DML, 21 mm DML, 20 mm DML, 20/09/1961; Canary Islands ; 32º 31′ 0′′ N, 16º 49′ 30′′ W; depth <170 m . NHM 20240069, 3 sex unknown, 40 mm DML, 27 mm DML, 21 mm DML, 25/10/1966, Canary Islands , 32º 55′ 1′′ N, 16º 48′ 6′′ W, depth unknown. NHM 20240070, 1 sex unknown, 45 mm DML , 31/10/1969, North Atlantic , 21º 29′ 52′′ N, 25º31′W, depth <200 m . NHM 20240071, 1 sex unknown, 22 mm DML, 01/08/1987, North Atlantic , 40º 1′ 36′′ N, 21º 11′ W, depth 885– 775 m . NHM 20240072, 1 sex unknown, 12.7 mm DML, 26/07/1974, South Atlantic , 0º 20′ S, 22 º 30′W, depth 28– 10 m . NHM 20240073, 1 sex unknown, 18 mm DML, 29/10/1966, Madeira Islands , 32º 32′ 0′′ N, 16º 53′ 0′′ W, depth unknown. NHM 20240074, 1 sex unknown, 20 mm DML, date unknown, location unknown, depth <300 m . NHM 20240075, 1 sex unknown, 19 mm DML, 26/05/1964, Oman, 17º 6′ 54′′ N, 55º 27′ 0′′ E, depth <100 m . NHM 20240076, 1 sex unknown, 18 mm DML, date unknown, location unknown, depth unknown. NHM 20240078, 1 sex unknown, 25 DML, 07/06/1962, Venezuela, 11º 24′ 30′′ N, 67º 8′ 0′′ W, depth <400 m . NHM 20240080, 1 ♀, 225 mm DML, 1960–1969, South Africa, 33º 4′ S, 18º 0′ E, depth unknown. NHM 20240081 , 1 ♀, 165 mm DML, date unknown, South Africa, 29º 51′ S, 31º 0′ E, depth unknown. NHM 20240084 , 1♀, 130 mm DML, date unknown, South Africa, 33º 4′ S, 18º 0′ E, depth unknown. 254 Tasmin, 1 sex unknown, DML unknown, date unknown, Tasman Sea, 40ºS, 155ºE, depth unknown. ZMA. MOLL.2514234 , 3 specimens, 2 sexes unknown, DML unknown; 45 mm DML , 1♂ 60 mm DML, 14/06/1979, North East Atlantic Ocean , 33º 43′ N, 15º 30′ W, depth 200 m . ZMA. MOLL.2514233, 2 specimens, 1 sex unknown, 68 mm DML , 1♂ 63 mm DML, 13/06/1979, North East Atlantic Ocean , 37º 23′ N, 11º 04′ W, depth 200 m . RMNH.MOL.518384, 1 sex unknown, 44 mm DML, 04/08/1992, Gulf of Aden , 12º 9′ N, 47º15′E, depth unknown. RMNH.MOL.518385, 1 sex unknown, 19 mm DML , 04/08/1992, Gulf of Aden , 12º 9′ N, 47º 15′ E, depth unknown. RMNH.MOL.518386, 2 sex unknown, 12 mm DML, 15 mm DML , 28/08/1992, Indian Ocean, 7ºN, 53ºE, depth unknown. RMNH.MOL.518387, 1 sex unknown, 18 mm DML , 02/02/1993, Red Sea, 14º 34′ 48′′ N, 42º 19′ 47′′ E, depth unknown. RMNH.MOL.518389, 1 sex unknown, 19 mm DML , 04/02/1993, Red Sea 16º 0′ N, 41º 33′ 36′′ E, depth unknown. ZMA. MOLL.434784, 1 sex unknown, DML unknown, date unknown, South Georgia Island, 54º 8′ 60′′ S, 36º 27′ 0′′ E, depth unknown. ICM102 /2002 , 1♂, 67.2 mm DML, 26/04/1989, SE Atlantic , 28º 10′ S, 14º 33 E, 406 m depth .

Distribution: Specimens from the North Atlantic, Caribbean, South Africa, the Red Sea, and the Tasmanian Sea.

Remarks

Although careful morphological examinations were performed, it was not possible to group these specimens into morphospecies. Direct comparisons were challenging, as there were several ontogenetic stages and different degrees of conservation, ranging from entire specimens with well-preserved morphologies to fragments of heavily digested individuals. Variations in characteristics like rigidity, texture, and colour are possibly due to the action of digestive enzymes in individuals collected from the stomachs of whales (specimens NHM20240066, NHM20240080, NHM202400081, NHM20240084, and Tasmin254). However, some morphological characters were variable, and this information might be useful in future studies trying to solve other Ancistrocheirus cryptic species. A summary of the variation of the studied morphological characters is available in the Supporting Information, Table S2, while the raw data of the measures is available in the Supporting Information, Table S3. These tables and the following paragraphs should not be interpreted as the description of a single species but as the description of the variation found among the studied individuals, which probably represent several species.

Spermatophore morphology from ZMA. MOLL.2514234 ( DML 60 mm, north-east Atlantic) was found to be similar to previous descriptions from Hoving et al. (2006) based on much larger specimens collected in South Africa. For ZMA. MOLL.2514234, the SpC was 1, while Hoving et al. (2006) found an SpC of 2–77. The SpLI of the specimen studied here was 41.4% of DML, within the range Hoving and Lipinski (2014) found of 22%–46%. As Hoving and Lipinski (2014) calculated the spermatophore measurements as a percentage of SpL, the values from this research were translated here to match their indexes. The CBLI of 18.5% SpL of ZMA. MOLL.2514234 is slightly larger than the South African Ancistrocheirus sp. from Hoving et al. (2006), which was 7%–14% SpL. The EALI of 30.4% SpL of ZMA. MOLL.2514234 falls within the described range of 21%–38% SpL from Hoving et al. (2006).

Currently, all molecular data collected from South African specimens have been found to all belong to the same species, Ancistrocheirus sp. 5 . Four specimens from South Africa have been morphologically examined ( NHM 20240080; NHM20240081; NHM20240084; NHM20240066), and all were collected from the stomach of sperm whales and were partially digested. Morphological differences can be observed in the lower beak of NHM20240080 compared to specimens from other locations. The specimen has a small rostrum compared to all other beak features, e.g. the lower beak length is 408% LRL, in comparison to a beak length of 242.4%–362.3% LRL in A. alessandrinii and 260% LRL in Ancistrocheirus sp. A . The tentacle clubs of NHM20240066 and NHM20240084 are large, representing 48.5%–53.8% of DML (N = 2), especially when compared to A. alessandrinii (N = 4) with a CLI of 26.0%–31.3% of DML, and to Ancistrocheirus sp. A (N = 2) with a CLI of 23.9%–26.7% of DML. Arm hook morphology among these South African specimens was often malformed with twisted hooks. All adult miscellaneous specimens from which hooks were extracted were collected from the stomach of sperm whales, so the digestive acids might have altered the arm hook shape. Hoving and Lipinski (2014) described the largest Ancistrocheirus female ever reported with 540 mm of DML, while the largest specimen in this study has a DML of 265 mm. The largest specimen examined from outside South Africa had a DML of 210 mm.

Hoving et al. (2006) found approximately half of the males to have nidamental glands, and these males were also found to be larger than males lacking nidamental glands ( Hoving and Lipinski 2014). Here, none of the examined males were found to have nidamental glands, however the sample size for males was low, and none of the males originated from South Africa. Individual ICMC 102/2002 originates from Namibia, near South Africa. This specimen was a maturing male of 67.2 mm DML with no nidamental glands.